JP2022019154A - Liquid discharge device, and control method of the liquid discharge device - Google Patents

Abstract

[Problem] To provide a liquid ejection device and a method for controlling a liquid ejection device that can reduce the risk of the liquid ejection head drawing in liquid from the nozzles. [Solution] The device includes a liquid ejection head 23 that ejects liquid from nozzles 22 provided on a nozzle surface 21, a first storage section 33 that communicates with a liquid storage section 24 that stores liquid and in which a first liquid level 66 fluctuates within a range lower than the nozzle surface 21, a second storage section 35 that communicates with the first storage section 33 via a communication passage 34 and to which liquid is supplied from the first storage section 33 due to a head difference, a supply flow passage 37 that supplies liquid from the second storage section 35 to the liquid ejection head 23, a pressure variable mechanism 47 that reduces the pressure inside the first storage section 33 and pressurizes the second storage section 35, and a first valve 36 that can close the communication passage 34 when the pressure variable mechanism 47 pressurizes the second storage section 35. [Selected Figure] Figure 2

Description

The present invention relates to a liquid discharge device such as a printer and a control method for the liquid discharge device.

For example, as in Patent Document 1, there is a recording device which is an example of a liquid ejection device which ejects ink which is an example of liquid from a nozzle formed in a recording head which is an example of a liquid ejection head and prints. The recording device sucks ink from the nozzle by operating the suction pump with the cap in contact with the recording head.

Japanese Unexamined Patent Publication No. 2014-024189

In the suction cleaning that sucks and discharges the liquid, the pressure inside the liquid discharge head becomes negative even after the suction cleaning is completed. Therefore, the recording head may draw the liquid adhering to the nozzle surface on which the nozzle is provided by suction from the nozzle, and the liquids may be mixed in the recording head.

The liquid discharge device that solves the above problems communicates with the liquid discharge head that discharges the liquid from the nozzle provided on the nozzle surface and the liquid storage portion that stores the liquid, and the liquid level is in a range lower than that of the nozzle surface. From the fluctuating first storage section, the second storage section in which the liquid is supplied from the first storage section due to the difference in head while communicating with the first storage section via a communication passage, and the second storage section. A supply flow path for supplying the liquid to the liquid discharge head, a pressure variable mechanism for depressurizing the inside of the first storage section and pressurizing the inside of the second storage section, and a pressurization in the second storage section by the pressure variable mechanism. It is provided with a first valve that can sometimes close the communication passage.

A control method for a liquid discharge device that solves the above problems is a liquid discharge head that discharges liquid from a nozzle provided on the nozzle surface, a first storage unit that communicates with the liquid storage unit that stores the liquid, and the first storage unit. A second storage unit that communicates with the unit via a communication passage, a supply flow path that supplies the liquid from the second storage unit to the liquid discharge head, a first valve that can open and close the communication passage, and the first valve. A control method for a liquid discharge device including a pressure variable mechanism that depressurizes the inside of a storage unit and pressurizes the inside of the second storage unit, in which the communication passage is closed by the first valve and the pressure variable mechanism. The inside of the first storage unit is depressurized to supply the liquid from the liquid storage unit to the first storage unit, and the communication passage is opened by the first valve and the first by the pressure variable mechanism. The decompression in the storage section is released, the liquid is supplied from the first storage section to the second storage section by a head difference, the communication passage is closed again by the first valve, and the pressure variable mechanism. The inside of the second storage portion is pressurized and the liquid is discharged from the nozzle, and the pressure discharge including is performed.

The perspective view of one Embodiment of a liquid discharge device. Schematic diagram of the supply mechanism and drive mechanism provided in the liquid discharge device. A flowchart showing a full filling routine. A flow chart showing a liquid circulation routine. A flow chart showing a print routine. A flowchart showing a pressurized discharge routine. A flowchart showing the accumulator discharge routine. A flowchart showing a slightly pressurized discharge routine. A flowchart showing a head replacement routine.

Hereinafter, an embodiment of a liquid discharge device and a control method for the liquid discharge device will be described with reference to the drawings. The liquid ejection device is, for example, an inkjet printer that ejects and prints ink, which is an example of a liquid, onto a medium such as paper.

In the drawing, the direction of gravity is shown by the Z axis, and the direction along the horizontal plane is shown by the X axis and the Y axis, assuming that the liquid discharge device 11 is placed on the horizontal plane. The X-axis, Y-axis, and Z-axis are orthogonal to each other.

As shown in FIG. 1, the liquid discharge device 11 operates a medium storage unit 13 capable of accommodating a medium 12, a stacker 14 for receiving a printed medium 12, and an operation such as a touch panel for operating the liquid discharge device 11. A unit 15 may be provided. The liquid ejection device 11 may include an image reading unit 16 that reads an image of a document and an automatic feeding unit 17 that feeds the document to the image reading unit 16.

The liquid discharge device 11 includes a control unit 19 that controls various operations executed by the liquid discharge device 11. The control unit 19 is composed of, for example, a computer and a processing circuit including a memory, and controls according to a program stored in the memory.

As shown in FIG. 2, the liquid discharge device 11 supplies the liquid discharge head 23 that discharges the liquid from the nozzle 22 provided on the nozzle surface 21 and the liquid stored in the liquid storage unit 24 to the liquid discharge head 23. A mechanism 25 and a drive mechanism 26 for driving the supply mechanism 25 are provided. The liquid discharge device 11 may include a plurality of supply mechanisms 25. The plurality of supply mechanisms 25 may supply different types of liquids to the liquid discharge head 23. For example, the liquid ejection device 11 may eject ink of a plurality of colors supplied by a plurality of supply mechanisms 25 to perform color printing. One drive mechanism 26 may drive a plurality of supply mechanisms 25 together. The liquid discharge device 11 may include a plurality of drive mechanisms 26 that individually drive the plurality of supply mechanisms 25.

The liquid discharge head 23 may be detachably provided with respect to the main body of the liquid discharge device 11. The liquid discharge head 23 is arranged so that the nozzle surface 21 is tilted with respect to the horizontal. The liquid ejection head 23 may execute printing by ejecting the liquid to the medium 12 in an inclined posture. The liquid discharge head 23 of the present embodiment is a line type provided over the width direction of the medium 12. The liquid discharge head 23 may be configured as a serial type that prints while moving in the width direction of the medium 12.

The supply mechanism 25 opens and closes a mounting portion 28 to which the liquid accommodating portion 24 is detachably mounted, an introduction flow path 29 capable of introducing liquid from the liquid accommodating portion 24 mounted on the mounting portion 28, and an introduction flow path 29. A possible introduction valve 30 may be provided. The liquid storage unit 24 before being mounted on the mounting unit 28 may store a larger amount of liquid than the amount of liquid that the supply mechanism 25 can hold. The liquid accommodating portion 24 is attached to the mounting portion 28 and is connected to the upstream end of the introduction flow path 29. The introduction valve 30 is configured to have a check valve that allows the flow of liquid from the liquid storage unit 24 to the first storage unit 33 and restricts the flow of liquid from the first storage unit 33 to the liquid storage unit 24. Will be done.

The supply mechanism 25 includes a first storage unit 33 that stores the liquid supplied from the liquid storage unit 24 that stores the liquid, a communication passage 34 whose upstream end is connected to the first storage unit 33, and a downstream of the communication passage 34. A second reservoir 35, to which the ends are connected, is provided. The first storage unit 33 of the present embodiment is connected to the downstream end of the introduction flow path 29 and communicates with the liquid storage unit 24 via the introduction flow path 29. The second storage unit 35 communicates with the first storage unit 33 via the communication passage 34. The supply mechanism 25 includes a first valve 36 that can open and close the communication passage 34, and a supply flow path 37 that supplies liquid from the second storage unit 35 to the liquid discharge head 23. The supply mechanism 25 includes a second valve 38 provided in the supply flow path 37 between the second storage unit 35 and the liquid discharge head 23, and a recovery flow path for collecting liquid from the liquid discharge head 23 to the first storage unit 33. 39, a third valve 40 capable of opening and closing the recovery flow path 39, and a liquid chamber 41 provided in the recovery flow path 39 may be provided.

The liquid chamber 41 is provided in the recovery flow path 39 between the liquid discharge head 23 and the third valve 40. The liquid chamber 41 is partially composed of a flexible member 42, and the volume of the liquid chamber 41 changes as the flexible member 42 is deformed.

The liquid discharge head 23 may have a first connection portion 44 to which the recovery flow path 39 is connected and a second connection portion 45 to which the supply flow path 37 is connected. The recovery flow path 39 has an upstream end connected to the first connection portion 44 and a downstream end connected to the first storage portion 33. The upstream end of the supply flow path 37 is connected to the second storage portion 35, and the downstream end is connected to the second connection portion 45. In the tilted posture, the first connection portion 44 between the liquid discharge head 23 and the recovery flow path 39 may be arranged at a position higher than the second connection portion 45 between the liquid discharge head 23 and the supply flow path 37.

The drive mechanism 26 includes a pressure variable mechanism 47 that depressurizes the inside of the first storage unit 33 and pressurizes the inside of the second storage unit 35. The drive mechanism 26 may include a decompression flow path 48 for communicating the inside of the first storage unit 33 and the pressure variable mechanism 47, and a pressure sensor 49 capable of detecting the pressure in the decompression flow path 48. The drive mechanism 26 may include an atmospheric open passage 50 connected to the first storage unit 33, and a pressurizing flow path 51 for communicating the inside of the second storage unit 35 with the pressure variable mechanism 47.

The drive mechanism 26 has an air chamber 53 separated by a liquid chamber 41 and a flexible member 42, a spring 54 provided in the air chamber 53, and an air flow path 55 connected to the air chamber 53. You may prepare. The spring 54 pushes the flexible member 42 to reduce the pressure fluctuation of the liquid in the recovery flow path 39 and the liquid discharge head 23.

The pressure variable mechanism 47 is a tube pump that sends out air by, for example, a roller rotating while crushing the tube. In a tube (not shown) included in the pressure variable mechanism 47, a decompression flow path 48 and an air flow path 55 are connected to one end, and a pressurization flow path 51 is connected to the other end. The pressure variable mechanism 47 is driven in the forward direction to send the air taken in from the decompression flow path 48 and the air flow path 55 to the pressurization flow path 51. The pressure variable mechanism 47 is driven in reverse to send the air taken in from the pressurizing flow path 51 to the depressurizing flow path 48 and the air flow path 55.

In the present embodiment, the pressurizing mechanism 57 includes a pressure variable mechanism 47, an air chamber 53, and an air flow path 55 that communicates the pressure variable mechanism 47 and the air chamber 53, and the pressurizing mechanism 57 is provided with the pressurizing mechanism 57. A liquid chamber 41 is added to form a slightly pressurized portion 58. The micro-pressurizing unit 58 has a liquid chamber 41 and a pressurizing mechanism 57 capable of pressurizing the flexible member 42 from the outside of the liquid chamber 41. The micro-pressurizing unit 58 is provided in the recovery flow path 39 between the liquid discharge head 23 and the third valve 40, and pressurizes the liquid in the recovery flow path 39.

Next, the first storage unit 33 will be described.
The first storage unit 33 may have a pressure reducing chamber 60 to which the pressure reducing flow path 48 is connected, and a float valve 61 capable of opening and closing the pressure reducing flow path 48. The first storage unit 33 includes a first storage chamber 62 for storing liquid, a liquid amount sensor 63 for detecting the amount of liquid stored in the first storage chamber 62, a first storage chamber 62, and a drive mechanism 26. It may have a first gas-liquid separation membrane 64 that separates it. The first gas-liquid separation membrane 64 is a membrane having a property of allowing a gas to pass through but not a liquid. For example, the first gas-liquid separation membrane 64 may be provided in the first storage chamber 62 so as to separate the first storage chamber 62 and the air opening passage 50. The first gas-liquid separation membrane 64 may be provided in the decompression chamber 60 so as to separate the first storage chamber 62 and the decompression flow path 48. The first storage unit 33 may include a sealing member 65 that can seal between the pressure reducing chamber 60 and the float valve 61.

The float valve 61 moves following the movement of the first liquid level 66 in the first storage unit 33. The float valve 61 contacts the seal member 65 when the height of the first liquid level 66 reaches a predetermined height, and closes the decompression chamber 60. That is, the float valve 61 of the present embodiment closes the decompression flow path 48 by separating the decompression chamber 60 and the first storage chamber 62.

In the present embodiment, the position of the first liquid level 66 when the float valve 61 closes the pressure reducing flow path 48 is referred to as a standard position. The standard position is a position lower than the nozzle surface 21. The first liquid level 66 fluctuates in a range lower than that of the nozzle surface 21.

Specifically, when the first liquid level 66 is located below the standard position, the float valve 61 is separated from the seal member 65, and the first storage chamber 62 communicates with the decompression chamber 60. When the pressure variable mechanism 47 decompresses the inside of the decompression chamber 60, the inside of the first storage unit 33 is also depressurized, and the liquid is supplied from the liquid storage unit 24 to the first storage unit 33. The first liquid level 66 rises by the amount of the supplied liquid. When the first liquid level 66 reaches the standard position, the float valve 61 closes the pressure reducing flow path 48. As a result, the depressurization in the first storage chamber 62 is stopped, and the inflow of the liquid from the liquid storage section 24 to the first storage section 33 is stopped.

The first liquid level 66 is lowered by supplying a liquid from the first storage unit 33 to the second storage unit 35. When the first liquid level 66 descends and the float valve 61 communicates the pressure reducing chamber 60 with the first storage chamber 62, the liquid is supplied from the liquid storage unit 24 to the first storage unit 33. Therefore, the first liquid level 66 moves below the standard position.

When the liquid contained in the liquid accommodating portion 24 runs out, the first liquid level 66 cannot rise to the standard position. In the liquid level sensor 63, the first liquid level 66 is located at the standard position, the first liquid level 66 is located at the replenishment position below the standard position, and the first liquid level 66 is at the full position above the standard position. It may be detected that it is located in. When the first liquid level 66 is located at the full position, the first storage unit 33 stores the maximum amount of liquid. The replenishment position is a position that serves as a guide for replenishing the liquid from the liquid storage unit 24 to the first storage unit 33. The control unit 19 determines that the liquid storage unit 24 is empty when the first liquid level 66 does not rise to the standard position even if the pressure inside the first storage unit 33 is reduced, and the liquid storage unit 24 is replaced or the liquid is replaced. The user may be instructed to replenish the container 24 with liquid.

The standard position of the present embodiment is located above the position where the downstream end of the recovery flow path 39 is connected in the first storage chamber 62. Therefore, when the first liquid level 66 is in the standard position, the liquid in the first storage unit 33 can be supplied to the liquid discharge head 23 via the recovery flow path 39.

Next, the second storage unit 35 will be described.
The second storage unit 35 may have a second storage chamber 68 for storing the liquid, and a second gas-liquid separation membrane 69 for separating the second storage chamber 68 and the pressurized flow path 51. Like the first gas-liquid separation membrane 64, the second gas-liquid separation membrane 69 is a membrane having a property of allowing a gas to pass through but not a liquid.

The liquid is supplied from the first storage unit 33 to the second storage unit 35 due to the head difference. The first valve 36 has a check valve that allows the flow of liquid from the first storage unit 33 to the second storage unit 35 and limits the flow of liquid from the second storage unit 35 to the first storage unit 33. May be configured. When the pressure inside the first storage chamber 62 and the inside of the second storage chamber 68 are set to atmospheric pressure, the second liquid level 70 of the liquid in the second storage portion 35 becomes the same height as the first liquid level 66. In other words, the second liquid level 70 fluctuates in a range lower than that of the nozzle surface 21. The liquid in the liquid discharge head 23 is maintained at a negative pressure due to the head difference from the liquid in the first storage unit 33 and the second storage unit 35. When the liquid is consumed by the liquid discharge head 23, the liquid stored in the second storage unit 35 is supplied to the liquid discharge head 23.

The first valve 36 closes the communication passage 34 when the pressure in the second reservoir 35 is larger than the pressure in the first reservoir 33. Therefore, the first valve 36 closes the communication passage 34 when the pressure in the second storage portion 35 is pressurized by the pressure variable mechanism 47. The first valve 36 closes the communication passage 34 when the pressure in the first storage portion 33 is reduced by the pressure variable mechanism 47. The opening and closing of the second valve 38 and the third valve 40 are controlled by the control unit 19. The second valve 38 is provided so as to be able to open and close the supply flow path 37 when pressurized by the pressure variable mechanism 47.

The drive mechanism 26 includes a thin tube portion 72 branched from the pressurized flow path 51 and a first selection valve 73a to a ninth selection valve 73i capable of opening and closing the flow path. The thin tube portion 72 is a thin and meandering tube to the extent that the flow of the liquid is greatly restricted with respect to the flow of air.

The first selection valve 73a communicates the pressure reducing flow path 48 and the air flow path 55 with the atmosphere by opening the valve. The second selection valve 73b communicates the pressure reducing flow path 48 and the air flow path 55 with the pressure sensor 49 by opening the valve. The third selection valve 73c opens the air flow path 55 by opening the valve, and allows the pressure variable mechanism 47 and the air chamber 53 to communicate with each other.

The fourth selection valve 73d opens the pressure reducing flow path 48 by opening the valve, and allows the pressure variable mechanism 47 and the pressure reducing chamber 60 to communicate with each other. The fifth selection valve 73e communicates the pressure flow path 51 with the pressure sensor 49 by opening the valve. The sixth selection valve 73f communicates the pressurized flow path 51 with the atmosphere by opening the valve. The seventh selection valve 73g opens the atmosphere opening path 50 by opening the valve, and allows the first storage chamber 62 to communicate with the atmosphere. The eighth selection valve 73h opens the pressurizing flow path 51 by opening the valve, and allows the pressure variable mechanism 47 and the second storage chamber 68 to communicate with each other. The ninth selection valve 73i communicates the pressurized flow path 51 with the thin tube portion 72 by opening the valve, and communicates the pressurized flow path 51 with the atmosphere via the thin tube portion 72.

When changing the pressure in the air chamber 53, the drive mechanism 26 opens the second selection valve 73b, the third selection valve 73c, and the sixth selection valve 73f, and closes the other selection valves. When the pressure variable mechanism 47 is driven in the normal direction in this state, the air in the air chamber 53 is discharged through the air flow path 55 and the pressurized flow path 51, and the pressure in the air chamber 53 decreases. When the pressure variable mechanism 47 is reversely driven in this state, air is sent to the air chamber 53 via the pressurizing flow path 51 and the air flow path 55, and the pressure in the air chamber 53 rises. At this time, the pressure sensor 49 may detect the pressure in the air flow path 55 and the air chamber 53. The control unit 19 may control the drive of the pressure variable mechanism 47 based on the detection result of the pressure sensor 49.

When the first storage unit 33 is opened to the atmosphere, the drive mechanism 26 opens the seventh selection valve 73 g and stops the drive of the pressure variable mechanism 47. The first storage chamber 62 communicates with the atmosphere through the open air passage 50 and becomes atmospheric pressure.

When the pressure inside the first storage unit 33 is reduced, the drive mechanism 26 opens the second selection valve 73b, the fourth selection valve 73d, and the sixth selection valve 73f, and closes the other selection valves. When the pressure variable mechanism 47 is driven in the normal direction in this state, the air in the decompression chamber 60 is discharged through the decompression flow path 48 and the pressurization flow path 51, and the pressure in the decompression chamber 60 decreases. At this time, the pressure sensor 49 may detect the pressure in the decompression flow path 48 and the decompression chamber 60. The control unit 19 may control the drive of the pressure variable mechanism 47 based on the detection result of the pressure sensor 49.

When the second storage unit 35 is opened to the atmosphere, the drive mechanism 26 opens the ninth selection valve 73i and stops the drive of the pressure variable mechanism 47. The second storage chamber 68 communicates with the atmosphere through the pressurized flow path 51 and the thin tube portion 72, and becomes atmospheric pressure.

When pressurizing the inside of the second storage unit 35, the drive mechanism 26 opens the first selection valve 73a, the fifth selection valve 73e, and the eighth selection valve 73h, and closes the other selection valves. When the pressure variable mechanism 47 is driven in the normal direction in this state, air flows into the second storage chamber 68 through the pressurizing flow path 51, and the pressure in the second storage chamber 68 rises. At this time, the pressure sensor 49 may detect the pressure in the pressurizing flow path 51 and the second storage chamber 68. The control unit 19 may control the drive of the pressure variable mechanism 47 based on the detection result of the pressure sensor 49.

Next, the control method of the liquid discharge device 11 will be described with reference to the flowcharts shown in FIGS. 3 to 9. Here, the step order of each control method can be arbitrarily replaced within a range that does not deviate from the purpose of each control method.

The full filling routine shown in FIG. 3 may be executed at the timing when the liquid storage unit 24 is first mounted on the mounting unit 28. The whole filling routine may be executed at the timing when the liquid accommodating portion 24 is mounted on the mounting portion 28 after the liquid discharge head 23 is replaced. In the initial state, the second valve 38, the third valve 40, and all the selection valves are closed.

In step S101, the control unit 19 depressurizes the inside of the first storage unit 33. In step S102, the control unit 19 determines whether or not the pressure detected by the pressure sensor 49 is below the predetermined pressure. The predetermined pressure is a negative pressure, which is larger than the negative pressure that causes the liquid to flow from the liquid storage unit 24 into the first storage unit 33 and raises the first liquid level 66. When the detected pressure detected by the pressure sensor 49 is equal to or higher than the predetermined pressure, step S102 becomes NO, and the control unit 19 waits until the detected pressure falls below the predetermined pressure. When the detected pressure falls below the predetermined pressure, step S102 becomes YES, and the control unit 19 shifts the process to step S103.

In step S103, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S104, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S105, the control unit 19 determines whether or not the supply time has elapsed since the first storage unit 33 and the second storage unit 35 were opened to the atmosphere. The supply time is the time required for the liquid to be supplied from the first storage unit 33 to the second storage unit 35 so that the heights of the first liquid level 66 and the second liquid level 70 are aligned. If the supply time has not elapsed, step S105 becomes NO, and the control unit 19 waits until the supply time has elapsed. When the supply time elapses, step S105 becomes YES, and the control unit 19 shifts the process to step S106. Here, step S103 and step S104 may be performed at the same time, or step S103 may be performed after step S104.

In step S106, the control unit 19 opens the second valve 38. In step S107, the control unit 19 opens the third valve 40. In step S108, the control unit 19 pressurizes the inside of the second storage unit 35. Here, step S106 and step S107 may be performed simultaneously with or after step S108, respectively.

In step S109, the control unit 19 determines whether or not the first filling time has elapsed since the inside of the second storage unit 35 was pressurized. The first filling time is the time required to fill the supply flow path 37 and the recovery flow path 39 with the liquid in the second storage portion 35. If the first filling time has not elapsed, step S109 becomes NO, and the control unit 19 waits until the first filling time has elapsed. When the first filling time elapses, step S109 becomes YES, and the control unit 19 shifts the process to step S110.

In step S110, the control unit 19 closes the second valve 38. In step S111, the control unit 19 closes the third valve 40. In step S112, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S113, the control unit 19 depressurizes the inside of the first storage unit 33. In step S114, the control unit 19 determines whether or not the pressure detected by the pressure sensor 49 is below the predetermined pressure. When the detected pressure detected by the pressure sensor 49 is equal to or higher than the predetermined pressure, step S114 becomes NO, and the control unit 19 waits until the detected pressure falls below the predetermined pressure. When the detected pressure falls below the predetermined pressure, step S114 becomes YES, and the control unit 19 shifts the process to step S115. Here, step S110 and step S111 may be performed simultaneously with step S112 or after step S112, respectively.

In step S115, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S116, the control unit 19 determines whether or not the supply time has elapsed since the first storage unit 33 was opened to the atmosphere. If the supply time has not elapsed, step S116 becomes NO, and the control unit 19 waits until the supply time has elapsed. When the supply time elapses, step S116 becomes YES, and the control unit 19 shifts the process to step S117.

In step S117, the control unit 19 closes the second valve 38. In step S118, the control unit 19 pressurizes the inside of the second storage unit 35. In step S119, the control unit 19 determines whether or not the second filling time has elapsed since the inside of the second storage unit 35 was pressurized. The second filling time is the time required to fill the liquid from the supply flow path 37 to the nozzle 22. If the second filling time has not elapsed, step S119 becomes NO, and the control unit 19 waits until the second filling time has elapsed. When the second filling time elapses, step S119 becomes YES, and the control unit 19 shifts the process to step S120. Here, step S117 may be performed at the same time as step S118 or after step S118.

In step S120, the control unit 19 stops driving the pressure variable mechanism 47. In step S121, the control unit 19 opens the second storage unit 35 to the atmosphere and ends the total filling routine. Here, step S120 may be performed at the same time as step S121 or after step S121.

Next, the operation in the case of performing the whole filling will be described.
As shown in FIG. 2, the liquid discharge device 11 decompresses the inside of the first storage unit 33 by the pressure variable mechanism 47, and supplies the liquid from the liquid storage unit 24 to the first storage unit 33. At this time, the pressure of the first storage unit 33 is lower than the pressure of the second storage unit 35. Therefore, the first valve 36 is closed. That is, the liquid discharge device 11 closes the communication passage 34 by the first valve 36 by reducing the pressure in the first storage unit 33.

When the pressure inside the first storage unit 33 is reduced, the liquid is supplied from the liquid storage unit 24 to the first storage unit 33, and the first liquid level 66 rises. Since the communication passage 34 is closed, no liquid is supplied to the second storage portion 35.

When the first liquid level 66 rises to the standard position, the float valve 61 separates the pressure reducing chamber 60 from the first storage chamber 62. In the first storage chamber 62, the depressurization is stopped and the inflow of the liquid into the first storage unit 33 is stopped. The pressure of the pressure reducing chamber 60 closed by the float valve 61 is further reduced. When the detected pressure detected by the pressure sensor 49 falls below a predetermined pressure, the control unit 19 stops driving the pressure variable mechanism 47 and opens the first storage unit 33 and the second storage unit 35 to the atmosphere.

When the first storage unit 33 and the second storage unit 35 are opened to the atmosphere, the first valve 36 is opened and the communication passage 34 is opened. Specifically, the liquid discharge device 11 opens the communication passage 34 by the first valve 36 and releases the depressurization in the first storage unit 33 by the pressure variable mechanism 47, so that the liquid is discharged from the first storage unit 33. 2 Water head difference is supplied to the storage unit 35. The first liquid level 66 is lowered by the amount of the liquid supplied to the second storage unit 35. The second liquid level 70 rises by the amount of the liquid supplied from the first storage unit 33. When the heights of the first liquid level 66 and the second liquid level 70 are aligned, the flow of the liquid from the first storage unit 33 to the second storage unit 35 is stopped.

The liquid discharge device 11 opens the second valve 38 and opens the supply flow path 37 by the second valve 38. The liquid discharge device 11 opens the third valve 40, and the recovery flow path 39 is opened by the third valve 40. The liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47. At this time, since the pressure of the second storage unit 35 is higher than the pressure of the first storage unit 33, the first valve 36 is closed. That is, the liquid discharge device 11 pressurizes the second storage unit 35 to close the communication passage 34 by the first valve 36. The liquid in the second storage unit 35 flows into the first storage unit 33 through the supply flow path 37, the liquid discharge head 23, and the recovery flow path 39. In other words, the liquid discharge device 11 fills the supply flow path 37 and the recovery flow path 39 with the liquid in the second storage unit 35.

Subsequently, the liquid discharge device 11 closes the second valve 38, and the supply flow path 37 is closed by the second valve 38. The liquid discharge device 11 closes the third valve 40, and the recovery flow path 39 is closed by the third valve 40. The liquid discharge device 11 opens the second storage unit 35 to the atmosphere.

The liquid discharge device 11 decompresses the inside of the first storage unit 33 by the pressure variable mechanism 47, and supplies the liquid from the liquid storage unit 24 to the first storage unit 33. At this time, since the pressure of the first storage unit 33 is lower than the pressure of the second storage unit 35, the first valve 36 is closed. That is, the liquid discharge device 11 closes the communication passage 34 by the first valve 36 by reducing the pressure in the first storage unit 33.

When the pressure inside the first storage unit 33 is reduced, the liquid is supplied from the liquid storage unit 24 to the first storage unit 33, and the first liquid level 66 rises. Since the communication passage 34 is closed, no liquid is supplied to the second storage portion 35. When the first liquid level 66 rises to the standard position and the detected pressure detected by the pressure sensor 49 falls below a predetermined pressure, the control unit 19 stops driving the pressure variable mechanism 47 and sets the first storage unit 33 to the atmosphere. Let it open.

Since the second storage unit 35 is opened to the atmosphere first, when the first storage unit 33 is opened to the atmosphere, the first valve 36 is opened and the communication passage 34 is opened. The liquid discharge device 11 opens the communication passage 34 by the first valve 36 and releases the depressurization in the first storage unit 33 by the pressure variable mechanism 47, so that the liquid is transferred from the first storage unit 33 to the second storage unit 35. Water head difference supply. When the heights of the first liquid level 66 and the second liquid level 70 are aligned, the liquid discharge device 11 opens the second valve 38 and opens the supply flow path 37. At this time, the third valve 40 is closed and the recovery flow path 39 is closed.

The liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47 in a state where the recovery flow path 39 is closed by the third valve 40. The liquid discharge device 11 closes the communication passage 34 again by the first valve 36 by making the pressure in the second storage unit 35 higher than the pressure in the first storage unit 33. Since the recovery flow path 39 is closed, the liquid in the second storage section 35 is supplied to the liquid discharge head 23 through the supply flow path 37 and discharged from the nozzle 22. The liquid discharge device 11 fills the liquid in the second storage unit 35 up to the nozzle 22 of the liquid discharge head 23.

When the liquid discharge head 23 is filled with the liquid, the liquid discharge device 11 may stop the driving of the pressure variable mechanism 47 and open the second storage unit 35 to the atmosphere. As a result, the first valve 36 is opened and the communication passage 34 is opened. The liquid in the first storage unit 33 is supplied to the second storage unit 35 via the communication passage 34. The liquid discharge device 11 may close the second valve 38.

The liquid circulation routine shown in FIG. 4 may be executed at the timing instructed to execute the liquid circulation. The liquid circulation is instructed to be executed, for example, after the entire filling is executed, and during the waiting time when printing or the like is not performed. The control unit 19 may periodically execute the liquid circulation routine.

In step S201, the control unit 19 opens the second valve 38. In step S202, the control unit 19 opens the third valve 40. In step S203, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S204, the control unit 19 pressurizes the inside of the second storage unit 35. Here, steps S201 to S204 may be performed at the same time, or the order may be changed.

In step S205, the control unit 19 determines whether or not the first liquid level 66 is located at the full position. If the first liquid level 66 is not located at the full position, step S205 becomes NO, and the control unit 19 waits until the first liquid level 66 is located at the full position. When the first liquid level 66 is located at the full position, step S205 becomes YES, and the control unit 19 shifts the process to step S206. In step S206, the control unit 19 closes the second valve 38. In step S207, the control unit 19 opens the second storage unit 35 to the atmosphere and ends the liquid circulation routine. Here, step S206 may be performed at the same time as step S207, or may be performed after step S207.

Next, the operation when the liquid circulation is performed will be described.
As shown in FIG. 2, the control unit 19 opens the second valve 38 and opens the supply flow path 37 by the second valve 38. The control unit 19 opens the third valve 40 and opens the recovery flow path 39 by the third valve 40.

The liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47, so that the liquid flows from the second storage unit 35 to the first storage unit 33 via the liquid discharge head 23. At this time, the pressure of the second storage unit 35 becomes higher than the pressure of the first storage unit 33. Therefore, the first valve 36 is closed. That is, the liquid discharge device 11 closes the communication passage 34 by the first valve 36 by pressurizing the inside of the second storage unit 35.

The print routine shown in FIG. 5 may be executed at the timing in which printing is instructed.
In step S301, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S302, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S303, the control unit 19 opens the second valve 38.

In step S304, the control unit 19 determines whether or not the discharge flow rate of the liquid generated by discharging the liquid from the nozzle 22 during printing is equal to or higher than the threshold value. The control unit 19 may calculate the discharge flow rate from the print data. When the discharge flow rate is equal to or higher than the threshold value, step S304 becomes YES, and the control unit 19 shifts the process to step S305. In step S305, the control unit 19 opens the third valve 40.

In step S304, when the discharge flow rate is smaller than the threshold value, step S304 becomes NO, and the control unit 19 shifts the process to step S306. In step S306, the control unit 19 closes the third valve 40. In step S307, the control unit 19 executes printing and ends the printing routine.

Here, step S301 and step S302 may be performed simultaneously with step S303 or after step S303, simultaneously with step S305 or after step S305, and simultaneously with step S306 or after step S306. You may go.

Next, the operation when the print routine is executed will be described.
As shown in FIG. 2, when the discharge flow rate when the liquid discharge head 23 discharges the liquid to the medium 12 is smaller than the threshold value, the control unit 19 opens the second valve 38 and the second valve 38 is opened. 3 The valve 40 is closed. That is, the control unit 19 executes printing in a state where the supply flow path 37 is opened by the second valve 38 and the recovery flow path 39 is closed by the third valve 40. Therefore, the liquid is supplied to the liquid discharge head 23 from the second storage unit 35 via the supply flow path 37.

When the discharge flow rate when the liquid discharge head 23 discharges the liquid to the medium 12 is equal to or higher than the threshold value, the control unit 19 opens the second valve 38 and the third valve 40. That is, the control unit 19 executes printing in a state where the supply flow path 37 is opened by the second valve 38 and the recovery flow path 39 is opened by the third valve 40. Therefore, the liquid is supplied from the second storage unit 35 to the liquid discharge head 23 via the supply flow path 37, and the liquid is also supplied from the first storage unit 33 via the recovery flow path 39.

The pressurized discharge routine shown in FIG. 6 is executed when the execution of the pressurized discharge is instructed, or when a discharge defect occurs in which the liquid cannot be normally discharged from the nozzle 22.
In step S401, the control unit 19 depressurizes the inside of the first storage unit 33. In step S402, the control unit 19 determines whether or not the pressure detected by the pressure sensor 49 is below the predetermined pressure. When the detected pressure detected by the pressure sensor 49 is equal to or higher than the predetermined pressure, step S402 becomes NO, and the control unit 19 waits until the detected pressure falls below the predetermined pressure. When the detected pressure falls below the predetermined pressure, step S402 becomes YES, and the control unit 19 shifts the process to step S403.

In step S403, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S404, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S405, the control unit 19 determines whether or not the supply time has elapsed since the first storage unit 33 and the second storage unit 35 were opened to the atmosphere. If the supply time has not elapsed, step S405 becomes NO, and the control unit 19 waits until the supply time has elapsed. When the supply time elapses, step S405 becomes YES, and the control unit 19 shifts the process to step S406. Here, step S403 and step S404 may be performed at the same time, or step S403 may be performed after step S404.

In step S406, the control unit 19 opens the second valve 38. In step S407, the control unit 19 closes the third valve 40. In step S408, the control unit 19 pressurizes the inside of the second storage unit 35. In step S409, the control unit 19 determines whether or not the pressurized discharge time has elapsed since the inside of the second storage unit 35 was pressurized. The pressurized discharge time is a time required for the pressure for pressurizing the second storage portion 35 to be transmitted to the nozzle 22 via the supply flow path 37, to discharge the liquid from the nozzle 22, and to restore the state of the nozzle 22. .. Here, step S406 and step S407 may be performed simultaneously with step S408 or after step S408, respectively.

Step S409 becomes NO until the pressurized discharge time elapses, and the control unit 19 waits until the pressurized discharge time elapses. When the pressurized discharge time elapses, step S409 becomes YES, and the control unit 19 shifts the process to step S410. In step S410, the control unit 19 closes the second valve 38. In step S411, the control unit 19 opens the second storage unit 35 to the atmosphere and ends the pressurized discharge routine. Here, step S410 may be performed at the same time as step S411, or may be performed after step S411.

Next, the operation in the case of performing pressurized discharge will be described.
As shown in FIG. 2, the liquid discharge device 11 decompresses the inside of the first storage unit 33 by the pressure variable mechanism 47. The liquid discharge device 11 closes the first valve 36 by lowering the pressure in the first storage unit 33 to be lower than the pressure in the second storage unit 35, and closes the communication passage 34 by the first valve 36. The liquid discharge device 11 decompresses the inside of the first storage unit 33 and supplies the liquid from the liquid storage unit 24 to the first storage unit 33. Since the communication passage 34 is closed, the liquid is supplied to the first storage unit 33 and the first liquid level 66 rises, whereas the liquid is not supplied to the second storage unit 35.

When the first liquid level 66 rises to the standard position and the float valve 61 separates the pressure reducing chamber 60 and the first storage chamber 62, the detected pressure detected by the pressure sensor 49 falls below the predetermined pressure. When the pressure detected by the pressure sensor 49 falls below a predetermined pressure while the pressure in the first storage unit 33 is being reduced by the pressure variable mechanism 47, the liquid discharge device 11 has the first storage unit 33 by the pressure variable mechanism 47. You may release the depressurization inside. The liquid discharge device 11 stops the drive of the pressure variable mechanism 47 and opens the first storage unit 33 and the second storage unit 35 to the atmosphere.

When the first storage unit 33 and the second storage unit 35 are opened to the atmosphere, the first valve 36 opens and the communication passage 34 is opened. Therefore, the liquid discharge device 11 opens the communication passage 34 by the first valve 36 and releases the depressurization in the first storage unit 33 by the pressure variable mechanism 47, so that the liquid is discharged from the first storage unit 33 to the second storage unit 33. The head difference is supplied to 35. When the heights of the first liquid level 66 and the second liquid level 70 are aligned, the liquid discharge device 11 opens the second valve 38 and opens the supply flow path 37. At this time, the third valve 40 is closed and the recovery flow path 39 is closed.

The liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47 and discharges the liquid from the nozzle 22. That is, the liquid discharge device 11 closes the communication passage 34 again by the first valve 36 by making the pressure in the second storage unit 35 higher than the pressure in the first storage unit 33. The liquid in the second storage unit 35 is supplied to the liquid discharge head 23 through the supply flow path 37, and is discharged from the nozzle 22 because the recovery flow path 39 is closed.

The accumulator discharge routine shown in FIG. 7 may be executed when the execution of the accumulator discharge is instructed, or when the discharge defect is not improved even if the pressure discharge is executed.
In step S501, the control unit 19 depressurizes the inside of the first storage unit 33. In step S502, the control unit 19 determines whether or not the pressure detected by the pressure sensor 49 is below the predetermined pressure. When the detected pressure detected by the pressure sensor 49 is equal to or higher than the predetermined pressure, step S502 becomes NO, and the control unit 19 waits until the detected pressure falls below the predetermined pressure. When the detected pressure falls below the predetermined pressure, step S502 becomes YES, and the control unit 19 shifts the process to step S503.

In step S503, the control unit 19 opens the first storage unit 33 to the atmosphere. In step S504, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S506, the control unit 19 closes the second valve 38. In step S507, the control unit 19 closes the third valve 40. In step S508, the control unit 19 determines whether the execution of the first accumulator discharge is instructed or the execution of the second accumulator discharge, which stores less pressure than the first accumulator discharge, is instructed among the accumulator discharges. When the first accumulator discharge is executed, step S508 becomes YES, and the control unit 19 shifts the process to step S509. In step S509, the control unit 19 sets the accumulator time to the first time.

When the second accumulator discharge is executed in step S508, step S508 becomes NO, and the control unit 19 shifts the process to step S510. In step S510, the control unit 19 sets the accumulator time to a second time shorter than the first time.

In step S511, the control unit 19 pressurizes the inside of the second storage unit 35. In step S512, the control unit 19 determines whether or not the accumulator time, which is an example of a predetermined time, has elapsed since the pressurization in the second storage unit 35 was started. If the accumulator time has not elapsed, step S512 becomes NO, and the control unit 19 waits until the accumulator time elapses. When the accumulator time elapses, step S512 becomes YES, and the control unit 19 shifts the process to step S513.

In step S513, the control unit 19 opens the second valve 38. In step S514, the control unit 19 determines whether or not the accumulator / discharge time has elapsed since the second valve 38 was opened. The accumulated pressure discharge time is the time required for the pressure stored in the second storage unit 35 to be transmitted to the nozzle 22 via the supply flow path 37 and to discharge the liquid from the nozzle 22.

Step S514 becomes NO until the accumulator discharge time elapses, and the control unit 19 waits until the accumulator discharge time elapses. When the accumulator discharge time elapses, step S514 becomes YES, and the control unit 19 shifts the process to step S515. In step S515, the control unit 19 closes the second valve 38. In step S516, the control unit 19 opens the second storage unit 35 to the atmosphere and ends the accumulator discharge routine.

Here, steps S506 and S507 may be performed at the same time as the start of pressurization in step S511, or immediately after the start of pressurization in step S511, respectively. Further, step S515 may be performed at the same time as step S516 or after step S516. Further, step S515 does not have to be performed.

Next, the operation when accumulating and discharging is performed will be described.
As shown in FIG. 2, the liquid discharge device 11 decompresses the inside of the first storage unit 33 by the pressure variable mechanism 47. The liquid discharge device 11 closes the first valve 36 by lowering the pressure in the first storage unit 33 to be lower than the pressure in the second storage unit 35, and closes the communication passage 34 by the first valve 36. The liquid discharge device 11 decompresses the inside of the first storage unit 33 and supplies the liquid from the liquid storage unit 24 to the first storage unit 33. Since the communication passage 34 is closed, the liquid is supplied to the first storage unit 33 and the first liquid level 66 rises, whereas the liquid is not supplied to the second storage unit 35.

When the first liquid level 66 rises to the standard position and the float valve 61 separates the pressure reducing chamber 60 and the first storage chamber 62, the detected pressure detected by the pressure sensor 49 falls below the predetermined pressure. When the pressure detected by the pressure sensor 49 falls below a predetermined pressure while the pressure in the first storage unit 33 is being reduced by the pressure variable mechanism 47, the liquid discharge device 11 has the first storage unit 33 by the pressure variable mechanism 47. You may release the depressurization inside. The liquid discharge device 11 stops the drive of the pressure variable mechanism 47 and opens the first storage unit 33 and the second storage unit 35 to the atmosphere.

When the first storage unit 33 and the second storage unit 35 are opened to the atmosphere, the first valve 36 opens and the communication passage 34 is opened. The liquid discharge device 11 opens the communication passage 34 by the first valve 36 and releases the depressurization in the first storage unit 33 by the pressure variable mechanism 47, so that the liquid is transferred from the first storage unit 33 to the second storage unit 35. Water head difference supply.

The liquid discharge device 11 closes the second valve 38, and the supply flow path 37 is closed by the second valve 38. The liquid discharge device 11 closes the third valve 40, and the recovery flow path 39 is closed by the third valve 40. The liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47. The liquid discharge device 11 closes the first valve 36 by making the pressure in the second storage section 35 higher than the pressure in the first storage section 33, and closes the communication passage 34 again by the first valve 36. .. With the communication flow path 34 and the supply flow path 37 closed, the liquid discharge device 11 pressurizes the inside of the second storage unit 35 for a pressure accumulation time by the pressure variable mechanism 47.

The magnitude of the pressure stored in the second storage section 35 is proportional to the time for pressurizing the inside of the second storage section 35 with the communication passage 34 and the supply flow path 37 closed. In the first pressure accumulation discharge, the time for pressurizing the inside of the second storage unit 35 by the pressure variable mechanism 47 is the first time. The second accumulator discharge is a second time in which the time for pressurizing the inside of the second storage unit 35 by the pressure variable mechanism 47 is shorter than the first time. The pressure stored in the first accumulator discharge is larger than the pressure stored in the second accumulator discharge. That is, in the first pressure accumulation discharge, the supply flow path 37 is opened by the second valve 38 when the inside of the second storage unit 35 is pressurized by the first pressure. The second accumulator discharge opens the supply flow path 37 by the second valve 38 when the inside of the second storage portion 35 is pressurized with a second pressure lower than the first pressure.

When the accumulator and discharge time elapses after pressurizing the inside of the second storage unit 35, the liquid discharge device 11 opens the second valve 38, opens the supply flow path 37 by the second valve 38, and liquid from the nozzle 22. To discharge.

The micropressurized discharge routine shown in FIG. 8 may be executed when the execution of the micropressurized discharge is instructed.
In step S601, the control unit 19 opens the second valve 38. In step S602, the control unit 19 opens the third valve 40. In step S603, the control unit 19 depressurizes the air chamber 53. In step S604, the control unit 19 determines whether or not the depressurization time has elapsed since the depressurization of the air chamber 53. The depressurizing time is the time required to deform the flexible member 42 and maximize the volume of the liquid chamber 41.

Step S604 becomes NO until the decompression time elapses, and the control unit 19 waits until the decompression time elapses. When the depressurization time elapses, step S604 becomes YES, and the control unit 19 shifts the process to step S605. In step S605, the control unit 19 closes the second valve 38. In step S606, the control unit 19 closes the third valve 40. In step S607, the control unit 19 pressurizes the air chamber 53.

In step S608, the control unit 19 determines whether or not the slight pressurization time has elapsed since the air chamber 53 was pressurized. The slight pressurization time is the time required for the pressure for pressurizing the air chamber 53 to be transmitted to the nozzle 22 via the liquid chamber 41 and the recovery flow path 39.

Step S608 becomes NO until the slight pressurization time elapses, and the control unit 19 waits until the slight pressurization time elapses. When the slight pressurization time elapses, step S608 becomes YES, and the control unit 19 shifts the process to step S609. In step S609, the control unit 19 opens the air chamber 53 to the atmosphere and ends the micropressurized discharge routine.

Here, step S601 and step S602 may be performed simultaneously with step S603 or after step S603, respectively. Further, steps S605 and S606 may be performed during step S603, at the same time as the end of step S603, or after the end of step S603, respectively. Further, steps S605 and S606 may be performed simultaneously with or after step S607, respectively.

Next, the operation when slightly pressurized discharge is performed will be described.
As shown in FIG. 2, the control unit 19 opens the supply flow path 37 and the recovery flow path 39 by opening the second valve 38 and the third valve 40. The control unit 19 decompresses the air chamber 53 and deforms the flexible member 42 to increase the volume of the liquid chamber 41. The liquid flows into the liquid chamber 41 from the first storage unit 33 via the recovery flow path 39, and the liquid flows from the second storage unit 35 through the supply flow path 37 and the recovery flow path 39.

When the volume of the liquid chamber 41 becomes maximum, the control unit 19 closes the second valve 38, and the second valve 38 closes the supply flow path 37. The control unit 19 closes the third valve 40, and the recovery flow path 39 is closed by the third valve 40. In this state, the liquid discharge device 11 pressurizes the flexible member 42 by sending pressurized air to the air chamber 53 by the pressure variable mechanism 47. That is, the liquid discharge device 11 pressurizes the flexible member 42 by the pressurizing mechanism 57 and discharges the liquid from the nozzle 22. The pressurizing mechanism 57 pressurizes the liquid chamber 41 with a pressure that breaks the meniscus formed in the nozzle 22. The amount of liquid discharged from the liquid discharge head 23 by the slightly pressurized discharge is smaller than the amount of the liquid discharged from the liquid discharge head 23 by the pressurized discharge.

The head replacement routine shown in FIG. 9 may be executed when the liquid discharge head 23 is replaced.
In step S701, the control unit 19 determines whether or not the liquid storage unit 24 has been removed from the mounting unit 28. When the liquid storage unit 24 is mounted on the mounting unit 28, step S701 becomes NO, and the control unit 19 waits until the liquid storage unit 24 is removed. When the liquid accommodating unit 24 is removed, step S701 becomes YES, and the control unit 19 shifts the process to step S702.

In step S702, the control unit 19 opens the second valve 38. In step S703, the control unit 19 closes the third valve 40. In step S704, the control unit 19 pressurizes the inside of the second storage unit 35. In step S705, the control unit 19 determines whether or not the first discharge time has elapsed since the inside of the second storage unit 35 was pressurized. The first discharge time is the time required for discharging the liquid stored in the second storage unit 35 through the supply flow path 37 and the liquid discharge head 23.

Step S705 becomes NO until the first discharge time elapses, and the control unit 19 waits until the first discharge time elapses. When the first discharge time elapses, step S705 becomes YES, and the control unit 19 shifts the process to step S706. In step S706, the control unit 19 opens the third valve 40.

In step S707, the control unit 19 determines whether or not the second discharge time has elapsed since the third valve 40 was opened. The second discharge time is the time required to recover the liquid in the recovery flow path 39 to the first storage unit 33.

Step S707 becomes NO until the second discharge time elapses, and the control unit 19 waits until the second discharge time elapses. When the second discharge time elapses, step S707 becomes YES, and the control unit 19 shifts the process to step S708. In step S708, the control unit 19 closes the second valve 38. In step S709, the control unit 19 closes the third valve 40.

In step S710, the control unit 19 opens the second storage unit 35 to the atmosphere. In step S711, the control unit 19 determines whether or not the liquid discharge head 23 has been replaced. If the liquid discharge head 23 has not been replaced, step S711 becomes NO, and the control unit 19 waits until the liquid discharge head 23 is replaced. When the liquid discharge head 23 is replaced, step S711 becomes YES, and the control unit 19 ends the head replacement routine.

Here, steps S702 and S703 may be performed at the same time as the start of pressurization in step S704 or immediately after the start of pressurization in step S704, respectively. Further, step S708 and step S709 may be performed simultaneously with or after step S710, respectively.

Next, the head replacement routine will be described.
As shown in FIG. 2, when the liquid discharge head 23 is replaced, the operator executes the head replacement routine and removes the liquid storage section 24 from the mounting section 28. Subsequently, the control unit 19 opens the second valve 38 and opens the supply flow path 37 by the second valve 38. The control unit 19 closes the third valve 40, and the recovery flow path 39 is closed by the third valve 40. In this state, the control unit 19 pressurizes the inside of the second storage unit 35.

Specifically, the liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47, and discharges the liquid from the second storage unit 35 to the liquid discharge head 23 from the nozzle 22. At this time, since the pressure of the second storage unit 35 is higher than the pressure of the first storage unit 33, the first valve 36 is closed. That is, the liquid discharge device 11 pressurizes the second storage unit 35 to close the communication passage 34 by the first valve 36.

When the liquid in the second storage unit 35, the supply flow path 37, and the liquid discharge head 23 is discharged, the control unit 19 opens the third valve 40, and the recovery flow path 39 is opened by the third valve 40. do. That is, the liquid discharge device 11 pressurizes the inside of the second storage unit 35 by the pressure variable mechanism 47, and collects the liquid in the recovery flow path 39 to the first storage unit 33. The operator replaces the liquid discharge head 23 with the liquid drained from the supply flow path 37, the liquid discharge head 23, and the recovery flow path 39.

The effect of this embodiment will be described.
(1) The communication passage 34 communicating with the first storage unit 33 and the supply passage 37 communicating with the liquid discharge head 23 are connected to the second storage unit 35. The communication passage 34 can be closed by the first valve 36 when the pressure variable mechanism 47 pressurizes the inside of the second storage portion 35. Therefore, the liquid in the pressurized second storage portion 35 is supplied to the liquid discharge head 23 via the supply flow path 37. Therefore, the liquid can be discharged from the nozzle 22 by pressurizing the liquid in the liquid discharge head 23, and the possibility that the liquid discharge head 23 draws the liquid from the nozzle 22 can be reduced.

(2) When the pressure in the first storage unit 33 is reduced by the pressure variable mechanism 47, the liquid is supplied from the liquid storage unit 24. When the height of the liquid level in the first storage unit 33 reaches a predetermined height, the float valve 61 closes the decompression flow path 48 and stops the decompression in the first storage unit 33. Therefore, the possibility that the liquid overflows from the first storage unit 33 can be reduced.

(3) When the pressure variable mechanism 47 pressurizes the inside of the second storage section 35 with the first valve 36 closing the communication passage 34 and the second valve 38 closing the supply flow path 37, the second storage section Pressurized pressure is stored in 35. Therefore, by opening the second valve 38 in a state where the pressure in the second storage portion 35 is increased, a high pressure can be transmitted to the liquid discharge head 23, and for example, a thickened liquid can be easily discharged.

(4) When the pressure variable mechanism 47 pressurizes the inside of the second storage unit 35 with the third valve 40 closed, the liquid is discharged from the liquid discharge head 23. When the pressure variable mechanism 47 pressurizes the inside of the second storage unit 35 with the third valve 40 open, the liquid in the liquid discharge head 23 is collected in the first storage unit 33 through the collection flow path 39. Therefore, for example, maintenance can be selected and performed according to the state of air bubbles in the supply flow path 37, the state of the nozzle 22, and the like.

(5) For example, when driving the first valve 36 to close the communication passage 34, a drive source for driving the first valve 36 is required. In that respect, the first valve 36 has a check valve. Specifically, the first valve 36 allows the flow of the liquid supplied from the first storage unit 33 to the second storage unit 35 due to the head difference, while the inside of the second storage unit 35 is pressurized. In some cases, the flow of liquid from the second reservoir 35 to the first reservoir 33 is restricted. Therefore, the first valve 36 does not need to be driven, and the drive source can be reduced.

(6) In the pressurized discharge, the liquid is supplied in this order from the liquid storage unit 24 to the first storage unit 33, from the first storage unit 33 to the second storage unit 35, and from the second storage unit 35 to the liquid discharge head 23, and the liquid is discharged. The liquid is discharged from the nozzle 22 provided on the head 23. The liquid in the second storage unit 35 is supplied to the liquid discharge head 23 via the supply flow path 37 by being pressurized by the pressure variable mechanism 47 in a state where the communication passage 34 is closed. Therefore, the liquid discharge device 11 can discharge the liquid from the nozzle 22 by pressurizing the liquid in the liquid discharge head 23, and can reduce the possibility that the liquid discharge head 23 draws the liquid from the nozzle 22.

(7) When the pressure detected by the pressure sensor 49 falls below a predetermined pressure, the pressure variable mechanism 47 releases the depressurization in the first storage unit 33. Therefore, even when the float valve 61 cannot close the pressure reducing flow path 48, for example, when the float valve 61 is displaced, the possibility that the liquid overflows from the first storage unit 33 can be reduced.

(8) Accumulation discharge is performed by pressurizing the inside of the second storage portion 35 by the pressure variable mechanism 47 with the first valve 36 closing the communication passage 34 and the second valve 38 closing the supply passage 37. , The pressing force is stored in the second storage unit 35. The accumulated pressure discharge can transmit the stored high pressure to the liquid discharge head 23 by opening the supply flow path 37 by the second valve 38 after pressurizing the inside of the second storage portion 35, for example, thickening. It is possible to easily discharge the discharged liquid.

(9) The entire filling is performed by combining the opening and closing of the first valve 36, the second valve 38, and the third valve 40 with the driving of the pressure variable mechanism 47, so that the liquid storage unit 24 fills the first storage unit 33 with liquid. The liquid can be filled in the second storage portion 35, the supply flow path 37, the liquid discharge head 23, and the recovery flow path 39. Therefore, the entire flow path can be filled with the liquid by performing the entire filling.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
The liquid discharge device 11 may include a wiping member (not shown) that wipes the nozzle surface 21. The liquid discharge device 11 may wipe the nozzle surface 21 with a wiping member after discharging the liquid from the nozzle 22. The liquid discharge device 11 may have the operator wipe the nozzle surface 21 before removing the liquid discharge head 23.

The control unit 19 may control the opening and closing of the first valve 36. The control unit 19 may close the communication passage 34 by the first valve 36 before depressurizing the inside of the first storage unit 33 and before pressurizing the inside of the second storage unit 35.

-For the second pressure accumulation discharge, the inside of the second storage unit 35 is pressurized for the first time with the first valve 36 and the second valve 38 closed, and the pressure in the second storage unit 35 becomes the first pressure. After that, the first valve 36 may be opened to reduce the pressure in the second storage unit 35 to the second pressure, and then the second valve 38 may be opened.

The slightly pressurized discharge may pressurize the liquid in the liquid chamber 41 by pushing the flexible member 42 with the spring 54. In this case, the control unit 19 decompresses the air chamber 53 to increase the volume of the liquid chamber 41, and then opens the air chamber 53 to the atmosphere. When the air chamber 53 reaches atmospheric pressure, the spring 54 pushes the liquid in the liquid chamber 41 and discharges the liquid from the liquid discharge head 23. In the case of the configuration in which the flexible member 42 is pushed by the spring 54, the spring 54 is included in the pressurizing mechanism 57.

The liquid discharge device 11 may execute printing with the recovery flow path 39 opened by the third valve 40 regardless of the discharge flow rate.
The liquid discharge head 23 may have a plurality of pressure chambers that individually communicate with the plurality of nozzles 22, a common liquid chamber that communicates with the plurality of pressure chambers, and a filter chamber that houses the filter. The first connecting portion 44 and the second connecting portion 45 are connected to at least one of a pressure chamber, a common liquid chamber, and a filter chamber. For example, when the first connection portion 44 and the second connection portion 45 are connected to the filter chamber, the liquid discharge device 11 collects the bubbles captured by the filter together with the liquid in the first storage unit 33 by performing liquid circulation. be able to. The liquid discharge device 11 may perform liquid circulation when bubbles are generated in the liquid discharge head 23.

-The second valve 38 and the third valve 40 may be closed and the supply flow path 37 and the recovery flow path 39 may be closed when the liquid discharge device 11 is on standby and when the power is turned off. By closing the supply flow path 37 and the recovery flow path 39, it is possible to reduce the possibility of liquid leaking from the liquid discharge head 23 even when vibration or impact is applied to the liquid discharge device 11, for example.

The amount of liquid that can be stored in the second storage unit 35 may be smaller than the amount of liquid required for pressurized discharge. In this case, the control unit 19 pressurizes the inside of the second storage unit 35 to supply the liquid from the second storage unit 35 to the liquid discharge head 23, and opens the second storage unit 35 to the atmosphere to open the first storage unit 35 to the first storage unit. The supply of the liquid from the 33 to the second storage unit 35 may be performed alternately.

The amount of liquid stored in the second storage unit 35 when the first liquid level 66 and the second liquid level 70 are located at the replenishment positions is the amount of liquid stored between the liquid storage unit 24 and the first storage unit 33. It may be larger than the amount required for printing. As a result, printing can be continued while the liquid is supplied from the liquid storage unit 24 to the first storage unit 33.

The amount of liquid contained in the liquid storage unit 24 may be smaller than the amount of liquid that can be held by the supply mechanism 25. In this case, the liquid accommodating portion 24 may be replaced during the entire filling of the supply mechanism 25 to be filled with the liquid.

For the accumulated pressure discharge, the communication passage 34 is closed by the first valve 36, the supply passage 37 is closed by the second valve 38, the inside of the second storage portion 35 is pressurized, and then the pressure sensor 49 reaches a predetermined pressure. When it is detected that the pressure has increased, the supply flow path 37 may be opened by the second valve 38. At this time, when the pressure sensor 49 detects that the pressure sensor 49 has reached the first pressure, the control unit 19 has a first pressure accumulating discharge that opens the supply flow path 37 and a second pressure smaller than the first pressure. A second accumulator discharge that opens the supply flow path 37 when it is detected may be performed. The first pressure and the second pressure are larger than the pressing force that pressurizes the second reservoir 35 at the time of pressurized discharge.

-The control unit 19 may depressurize the inside of the first storage unit 33 when the liquid flows from the recovery flow path 39 into the first storage unit 33.
The control unit 19 may remove air bubbles from the liquid by depressurizing the inside of the first storage unit 33 and expanding the air bubbles contained in the liquid stored in the first storage unit 33.

The liquid discharge device 11 may simultaneously perform depressurization in the first storage unit 33 and pressurization in the second storage unit 35. Specifically, the liquid discharge device 11 may open the fourth selection valve 73d and the eighth selection valve 73h, close the other selection valves, and drive the pressure variable mechanism 47 in the forward direction. At this time, the liquid discharge device 11 may open the second selection valve 73b and cause the pressure sensor 49 to detect the pressure in the pressure reducing flow path 48. The liquid discharge device 11 may open the fifth selection valve 73e and cause the pressure sensor 49 to detect the pressure in the pressurizing flow path 51.

The flow path resistance when the liquid moves in the decompression chamber 60 and the decompression flow path 48 may be larger than the flow path resistance when the first liquid level 66 rises in the first storage chamber 62. When the pressure in the first storage unit 33 is being reduced, the predetermined pressure as a guide for releasing the pressure reduction in the first storage unit 33 is a negative pressure, and the first liquid level 66 is set in the first storage chamber 62. It may be larger than the negative pressure to be increased and smaller than the negative pressure to move the liquid in the decompression chamber 60 or the decompression flow path 48.

When the liquid amount sensor 63 detects that the first liquid level 66 is located at the standard position, the liquid discharge device 11 may release the depressurization in the first storage unit 33.
The liquid discharge device 11 may release the depressurization in the first storage unit 33 by opening the first selection valve 73a and communicating the decompression flow path 48 with the atmosphere. In this case, the pressure variable mechanism 47 may continue to be driven.

-The whole filling, pressurized discharge, slightly pressurized discharge, and liquid circulation may be performed a plurality of times or may be performed in combination. When the amount of liquid that can be stored in the first storage unit 33 is smaller than the amount of liquid that can be filled in the supply flow path 37, the recovery flow path 39, and the liquid discharge head 23, it is supplied by performing the entire filling a plurality of times. The flow path 37, the recovery flow path 39, and the liquid discharge head 23 may be filled with liquid. For example, a slight pressure discharge may be performed after the entire filling. By combining the whole filling and the slightly pressurized discharge, it is possible to reduce the occurrence of discharge defects as compared with the case where only the whole filling is performed.

-The first storage unit 33 and the second storage unit 35 may be integrally configured.
The flexible member 42 may be formed of a rubber film, an elastomer film, a film, or the like.
The liquid chamber 41 may be provided in the supply flow path 37. The pressurizing mechanism 57 may pressurize the liquid chamber provided in the supply flow path 37.

-The pressure variable mechanism 47 may use a diaphragm pump, a piston pump, a gear pump, or the like.
The liquid discharge head 23 may discharge the liquid in a horizontal posture in which the nozzle surface 21 is horizontal and print on the medium 12. The liquid discharge head 23 may be provided so that the posture can be changed between a horizontal posture and an inclined posture.

The liquid discharge device 11 may be provided with an atmospheric opening path for opening the second storage unit 35 to the atmosphere separately from the pressurized flow path 51.
In the head replacement routine shown in FIG. 9, the control unit 19 may execute steps S702 to S705 again after executing step S710. As a result, the liquid collected in the first storage unit 33 can be discharged from the liquid discharge head 23.

The liquid ejection device 11 may be a liquid ejection device that ejects or ejects a liquid other than ink. The state of the liquid discharged as a minute amount of droplets from the liquid discharge device shall include those having a granular, tear-like, or thread-like tail. The liquid referred to here may be any material that can be discharged from the liquid discharge device. For example, the liquid may be in the state when the substance is in the liquid phase, and may be a highly viscous or low-viscosity liquid, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, etc. It shall contain a fluid such as a metal melt. The liquid includes not only the liquid as a state of the substance but also the particles of the functional material made of solid matter such as pigments and metal particles dissolved, dispersed or mixed in the solvent. Typical examples of the liquid include ink, liquid crystal, and the like as described in the above embodiment. Here, the ink includes general water-based inks, oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid discharge device, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an electroluminescence display, a surface light emitting display, a color filter, etc. in a dispersed or dissolved form is discharged. There is a device. The liquid discharge device may be a device for discharging a bioorganic substance used for producing a biochip, a device for discharging a liquid as a sample used as a precision pipette, a printing device, a micro dispenser, or the like. The liquid discharge device is a transparent resin such as an ultraviolet curable resin for forming a device that discharges lubricating oil pinpointly to a precision machine such as a watch or a camera, a micro hemispherical lens used for an optical communication element, an optical lens, and the like. It may be a device that discharges a liquid onto a substrate. The liquid discharge device may be a device that discharges an etching liquid such as an acid or an alkali in order to etch a substrate or the like.

The technical ideas and their actions and effects grasped from the above-described embodiments and modifications are described below.
(A) The liquid discharge device communicates with a liquid discharge head that discharges liquid from a nozzle provided on the nozzle surface and a liquid storage portion that stores the liquid, and the liquid level fluctuates in a range lower than the nozzle surface. The first storage section communicates with the first storage section via a communication passage, and the liquid is supplied from the first storage section by a head difference, and the liquid is supplied from the second storage section. The supply flow path for supplying the liquid to the discharge head, a pressure variable mechanism that depressurizes the inside of the first storage portion and pressurizes the inside of the second storage portion, and the pressure variable mechanism that pressurizes the inside of the second storage portion by the pressure variable mechanism. It is provided with a first valve capable of closing the communication passage.

According to this configuration, the second storage unit is connected to a communication passage that communicates with the first storage unit and a supply passage that communicates with the liquid discharge head. The communication passage can be closed by the first valve when the pressure variable mechanism pressurizes the inside of the second reservoir. Therefore, the pressurized liquid in the second reservoir is supplied to the liquid discharge head via the supply flow path. Therefore, the liquid can be discharged from the nozzle by pressurizing the liquid in the liquid discharge head, and the possibility that the liquid discharge head draws the liquid from the nozzle can be reduced.

(B) In the liquid discharge device, the first storage unit has a float valve that moves following the movement of the liquid level in the first storage unit, and the float valve has a height of the liquid level. When the predetermined height is reached, the decompression flow path that communicates the inside of the first storage unit with the pressure variable mechanism may be closed.

According to this configuration, when the pressure in the first storage unit is reduced by the pressure variable mechanism, the liquid is supplied from the liquid storage unit. When the height of the liquid level in the first reservoir reaches a predetermined height, the float valve closes the decompression flow path and stops the depressurization in the first reservoir. Therefore, the possibility that the liquid overflows from the first storage portion can be reduced.

(C) The liquid discharge device is provided in the supply flow path between the second storage unit and the liquid discharge head, and opens and closes the supply flow path when pressurization in the second storage unit by the pressure variable mechanism. A possible second valve may be further provided.

According to this configuration, when the pressure variable mechanism pressurizes the inside of the second storage section while the first valve closes the communication passage and the second valve closes the supply flow path, a pressing force is applied to the second storage section. Can be stored. Therefore, by opening the second valve in a state where the pressure in the second storage portion is increased, a high pressure can be transmitted to the liquid discharge head, and for example, a thickened liquid can be easily discharged.

(D) The liquid discharge device may further include a recovery flow path for collecting the liquid from the liquid discharge head to the first storage unit, and a third valve capable of opening and closing the recovery flow path.
According to this configuration, when the pressure variable mechanism pressurizes the inside of the second reservoir with the third valve closed, the liquid is discharged from the liquid discharge head. When the pressure variable mechanism pressurizes the inside of the second storage unit with the third valve open, the liquid in the liquid discharge head is collected in the first storage unit through the collection flow path. Therefore, for example, maintenance can be selected and performed according to the state of air bubbles in the supply flow path, the state of the nozzle, and the like.

(E) In the liquid discharge device, the first valve allows the flow of the liquid from the first storage portion to the second storage portion, and the liquid from the second storage portion to the first storage portion. It may have a check valve that limits the flow of.

For example, when driving the first valve to close the communication passage, a drive source for driving the first valve is required. In that respect, according to this configuration, the first valve has a check valve. Specifically, the first valve allows the flow of the liquid supplied from the first reservoir to the second reservoir due to the head difference, whereas the second valve allows the inside of the second reservoir to be pressurized. Limit the flow of liquid from the reservoir to the first reservoir. Therefore, the first valve does not need to be driven, and the drive source can be reduced.

(F) The control method of the liquid discharge device includes a liquid discharge head that discharges liquid from a nozzle provided on the nozzle surface, a first storage unit that communicates with the liquid storage unit that stores the liquid, and the first storage unit. A second storage unit communicating via a communication passage, a supply flow path for supplying the liquid from the second storage unit to the liquid discharge head, a first valve capable of opening and closing the communication passage, and the first storage unit. It is a control method of a liquid discharge device including a pressure variable mechanism for depressurizing the inside of a portion and pressurizing the inside of the second storage portion, in which the communication passage is closed by the first valve and the pressure variable mechanism is used. The inside of the first storage unit is depressurized to supply the liquid from the liquid storage unit to the first storage unit, the communication passage is opened by the first valve, and the inside of the first storage unit by the pressure variable mechanism. The depressurization of the liquid is released, the liquid is supplied from the first storage portion to the second storage portion by a head difference, the communication passage is closed again by the first valve, and the pressure variable mechanism is used. Pressurizing the inside of the second storage unit to discharge the liquid from the nozzle, and pressurizing and discharging including.

According to this method, the pressurized discharge is provided in the liquid discharge head by supplying the liquid from the liquid storage unit to the first storage unit, from the first storage unit to the second storage unit, and from the second storage unit to the liquid discharge head in this order. The liquid is discharged from the nozzle. The liquid in the second storage section is pressurized by the pressure variable mechanism with the communication passage closed, and is supplied to the liquid discharge head via the supply flow path. Therefore, the liquid discharge device can discharge the liquid from the nozzle by pressurizing the liquid in the liquid discharge head, and can reduce the possibility that the liquid discharge head draws the liquid from the nozzle.

(G) In the control method of the liquid discharge device, the liquid discharge device follows the movement of the liquid level in the first storage unit and the decompression flow path that communicates the inside of the first storage unit and the pressure variable mechanism. A float valve that can open and close the decompression flow path by moving and a pressure sensor that can detect the pressure in the decompression flow path are further provided, and the inside of the first storage unit is depressurized by the pressure variable mechanism. Occasionally, when the pressure detected by the pressure sensor falls below a predetermined pressure, the depressurization in the first storage unit by the pressure variable mechanism may be released.

According to this method, the pressure variable mechanism releases the depressurization in the first storage unit when the pressure detected by the pressure sensor falls below a predetermined pressure. Therefore, even when the float valve cannot close the pressure reducing flow path, for example, when the float valve is displaced, the possibility that the liquid overflows from the first storage portion can be reduced.

(H) The control method of the liquid discharge device is that the liquid discharge device is provided in the supply flow path between the second storage unit and the liquid discharge head, and the supply flow path can be opened and closed. The first valve closes the communication passage, and the pressure variable mechanism decompresses the inside of the first storage unit to supply the liquid from the liquid storage unit to the first storage unit. The first valve opens the communication passage, and the pressure variable mechanism releases the depressurization in the first storage portion to supply the liquid from the first storage portion to the second storage portion. That, the communication flow path is closed again by the first valve, the supply flow path is closed by the second valve, and the inside of the second storage portion is pressurized for a predetermined time by the pressure variable mechanism. After that, the supply flow path may be opened by the second valve to discharge the liquid from the nozzle, and the accumulated pressure discharge including the discharge may be performed.

According to this method, the accumulator discharge is performed by pressurizing the inside of the second storage portion by the pressure variable mechanism with the first valve closing the communication passage and the second valve closing the supply passage. The pressure is stored in the part. In the accumulated pressure discharge, after pressurizing the inside of the second storage portion, the supply flow path is opened by the second valve, so that the stored high pressure can be transmitted to the liquid discharge head, for example, the thickened liquid is discharged. It can be done easily.

(I) In the control method of the liquid discharge device, the liquid discharge device is provided in the supply flow path between the second storage unit and the liquid discharge head, and the second valve capable of opening and closing the supply flow path. Further, a recovery flow path for collecting the liquid from the liquid discharge head to the first storage portion and a third valve capable of opening and closing the recovery flow path are further provided, and the communication passage is closed by the first valve. At the same time, the pressure inside the first storage unit is depressurized by the pressure variable mechanism to supply the liquid from the liquid storage unit to the first storage unit, and the communication passage is opened by the first valve. The decompression in the first reservoir by the pressure variable mechanism is released, the liquid is supplied from the first reservoir to the second reservoir by a head difference, and the communication passage is closed again by the first valve. At the same time, the supply flow path is opened by the second valve, the inside of the second storage section is pressurized by the pressure variable mechanism, and the liquid in the second storage section is filled in the supply flow path and the recovery flow path. That is, the communication passage is closed by the first valve, the inside of the first storage portion is depressurized by the pressure variable mechanism, and the liquid is supplied from the liquid storage portion to the first storage portion. The first valve opens the communication passage and releases the depressurization in the first storage portion by the pressure variable mechanism to supply the liquid from the first storage portion to the second storage portion by a head difference. The first valve closes the communication passage again, the third valve closes the recovery flow path, and the pressure variable mechanism pressurizes the inside of the second storage section to pressurize the inside of the second storage section. The liquid may be filled up to the nozzle of the liquid discharge head, and the whole may be filled including.

According to this method, the total filling supplies the liquid from the liquid accommodating portion to the first storage portion by combining the opening and closing of the first valve, the second valve, and the third valve and the driving of the pressure variable mechanism. At the same time, the second storage section, the supply flow path, the liquid discharge head, and the recovery flow path can be filled with liquid. Therefore, the entire flow path can be filled with the liquid by performing the entire filling.

11 ... Liquid discharge device, 12 ... Medium, 13 ... Medium accommodating unit, 14 ... Stacker, 15 ... Operation unit, 16 ... Image reading unit, 17 ... Automatic feeding unit, 19 ... Control unit, 21 ... Nozzle surface, 22 ... Nozzle, 23 ... Liquid discharge head, 24 ... Liquid storage section, 25 ... Supply mechanism, 26 ... Drive mechanism, 28 ... Mounting section, 29 ... Introduction flow path, 30 ... Introduction valve, 33 ... First storage section, 34 ... Ream Passage, 35 ... 2nd reservoir, 36 ... 1st valve, 37 ... Supply flow path, 38 ... 2nd valve, 39 ... Recovery flow path, 40 ... 3rd valve, 41 ... Liquid chamber, 42 ... Flexible member , 44 ... 1st connection, 45 ... 2nd connection, 47 ... variable pressure mechanism, 48 ... decompression flow path, 49 ... pressure sensor, 50 ... open air path, 51 ... pressurization flow path, 53 ... air chamber, 54 ... Spring, 55 ... Air flow path, 57 ... Pressurization mechanism, 58 ... Slight pressurization section, 60 ... Decompression chamber, 61 ... Float valve, 62 ... First storage chamber, 63 ... Liquid volume sensor, 64 ... First air Liquid separation membrane, 65 ... Seal member, 66 ... First liquid level, 68 ... Second storage chamber, 69 ... Second gas-liquid separation membrane, 70 ... Second liquid level, 72 ... Thin tube portion, 73a ... First selection valve , 73b ... 2nd selection valve, 73c ... 3rd selection valve, 73d ... 4th selection valve, 73e ... 5th selection valve, 73f ... 6th selection valve, 73g ... 7th selection valve, 73h ... 8th selection valve, 73i ... 9th selection valve.

Claims (9)

A liquid discharge head that discharges liquid from a nozzle provided on the nozzle surface,
A first storage unit that communicates with the liquid storage unit that stores the liquid and whose liquid level fluctuates in a range lower than the nozzle surface.
A second storage unit that communicates with the first storage unit via a communication passage and is supplied with the liquid from the first storage unit due to a head difference.
A supply flow path for supplying the liquid from the second storage unit to the liquid discharge head,
A pressure variable mechanism that depressurizes the inside of the first storage section and pressurizes the inside of the second storage section.
A first valve capable of closing the communication passage at the time of pressurization in the second storage portion by the pressure variable mechanism, and
A liquid discharge device characterized by being provided with. The first reservoir has a float valve that moves following the movement of the liquid level in the first reservoir.
The float valve is characterized in that, when the height of the liquid level reaches a predetermined height, the pressure reducing flow path for communicating the inside of the first storage portion and the pressure variable mechanism is closed. The liquid discharge device according to. A second valve provided in the supply flow path between the second storage section and the liquid discharge head and capable of opening and closing the supply flow path when pressurizing the inside of the second storage section by the pressure variable mechanism is further provided. The liquid discharge device according to claim 1 or 2, wherein the liquid discharge device is characterized in that. A recovery flow path for collecting the liquid from the liquid discharge head to the first storage unit,
A third valve that can open and close the collection flow path,
The liquid discharge device according to any one of claims 1 to 3, further comprising. The first valve allows the flow of the liquid from the first reservoir to the second reservoir and limits the flow of the liquid from the second reservoir to the first reservoir. The liquid discharge device according to any one of claims 1 to 4, wherein the liquid discharge device is characterized by having. A liquid discharge head that discharges liquid from a nozzle provided on the nozzle surface, a first storage unit that communicates with the liquid storage unit that stores the liquid, and a second storage unit that communicates with the first storage unit via a communication passage. A supply flow path for supplying the liquid from the second storage section to the liquid discharge head, a first valve capable of opening and closing the communication passage, and the inside of the first storage section are depressurized to create the inside of the second storage section. It is a control method of a liquid discharge device provided with a pressure variable mechanism for pressurizing.
Closing the communication passage by the first valve and
The pressure is reduced in the first storage unit by the pressure variable mechanism, and the liquid is supplied from the liquid storage unit to the first storage unit.
The first valve opens the communication passage and releases the depressurization in the first storage portion by the pressure variable mechanism to supply the liquid from the first storage portion to the second storage portion by the head difference. ,
Closing the communication passage again by the first valve and
The pressure variable mechanism pressurizes the inside of the second reservoir to discharge the liquid from the nozzle.
A method for controlling a liquid discharge device, which comprises performing pressurized discharge including. The liquid discharge device can open and close the decompression flow path by communicating the inside of the first storage section and the pressure variable mechanism and following the movement of the liquid level in the first storage section. A float valve and a pressure sensor capable of detecting the pressure in the decompression flow path are further provided.
When the pressure detected by the pressure sensor falls below a predetermined pressure while the pressure in the first storage unit is being depressurized by the pressure variable mechanism, the depressurization in the first storage unit by the pressure variable mechanism is released. The control method of the liquid discharge device according to claim 6. The liquid discharge device is provided in the supply flow path between the second storage unit and the liquid discharge head, and further includes a second valve capable of opening and closing the supply flow path.
Closing the communication passage by the first valve and
The pressure is reduced in the first storage unit by the pressure variable mechanism, and the liquid is supplied from the liquid storage unit to the first storage unit.
The first valve opens the communication passage and releases the depressurization in the first storage portion by the pressure variable mechanism to supply the liquid from the first storage portion to the second storage portion by the head difference. ,
Closing the communication passage again by the first valve and
Closing the supply flow path by the second valve and
After pressurizing the inside of the second storage portion for a predetermined time by the pressure variable mechanism, the supply flow path is opened by the second valve to discharge the liquid from the nozzle.
The control method of the liquid discharge device according to claim 6 or 7, wherein the accumulator discharge including the above is performed. The liquid discharge device is provided in the supply flow path between the second storage unit and the liquid discharge head, and has a second valve capable of opening and closing the supply flow path and the first storage from the liquid discharge head. The unit is further provided with a recovery flow path for collecting the liquid and a third valve capable of opening and closing the recovery flow path.
The first valve closes the communication passage, and the pressure variable mechanism decompresses the inside of the first storage unit to supply the liquid from the liquid storage unit to the first storage unit.
The first valve opens the communication passage and releases the depressurization in the first storage portion by the pressure variable mechanism to supply the liquid from the first storage portion to the second storage portion by the head difference. ,
The communication flow path is closed again by the first valve, the supply flow path is opened by the second valve, and the inside of the second storage portion is pressurized by the pressure variable mechanism to release the liquid in the second storage portion. Filling the supply flow path and the recovery flow path,
The first valve closes the communication passage, and the pressure variable mechanism decompresses the inside of the first storage unit to supply the liquid from the liquid storage unit to the first storage unit.
The first valve opens the communication passage and releases the depressurization in the first storage portion by the pressure variable mechanism to supply the liquid from the first storage portion to the second storage portion by the head difference. ,
The communication passage is closed again by the first valve, the recovery flow path is closed by the third valve, and the inside of the second storage portion is pressurized by the pressure variable mechanism to press the liquid in the second storage portion. The control method for a liquid discharge device according to any one of claims 6 to 8, wherein the liquid discharge head is filled up to the nozzle, and the entire liquid discharge head is filled.

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