JP2018165050A - Liquid discharge apparatus and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide techniques capable of inhibiting liquid leakage from nozzles and entry of external air from the nozzles.SOLUTION: A liquid discharge apparatus comprises: a liquid chamber 42 in communication with a nozzle 41; a liquid chamber driving unit 43 that changes a volume of the liquid chamber to discharge liquid through the nozzle; a flow channel 31 which is connected to the liquid chamber; and a valve 33 that changes a volume of the flow channel to control a flow of the liquid. The liquid discharge apparatus executes at least one of: first control of increasing the volume of the liquid chamber in association with a decrease in the volume of the flow channel, such that a change amount of the volume of the liquid chamber is equal to or larger than a volume of the liquid flowing from the flow channel into the liquid chamber because of the decrease in the volume of the flow channel; and second control of decreasing the volume of the liquid chamber in association with an increase in the volume of the flow channel such that a change amount of the volume of the liquid chamber is equal to or larger than a volume of the liquid flowing from the liquid chamber out to the flow channel because of the increase in the volume of the flow channel.SELECTED DRAWING: Figure 4A

Description

  The present invention relates to a liquid ejection apparatus and a control method thereof.

  Conventionally, various liquid ejecting apparatuses for ejecting liquid in a liquid chamber from nozzles provided in the liquid chamber by changing the volume of the liquid chamber have been proposed. Some of such liquid ejection devices displace the inner wall surface of the liquid flow path connected to the liquid chamber to variably control the flow path resistance (for example, Patent Documents 1 and 2 below).

JP 2001-63047 A JP 2011-213094 A

  However, when the inner wall surface is displaced in the direction in which the cross-sectional area of the liquid flow path becomes smaller in order to increase the flow path resistance of the liquid flow path, the liquid is pushed out from the liquid flow path to the liquid chamber. Thus, the inventors of the present invention have found that there is a possibility that liquid may leak from the nozzle. In addition, when the inner wall surface is displaced in the direction of increasing the cross-sectional area of the liquid flow path, the liquid may flow out from the liquid chamber to the liquid flow path, and the outside air may be sucked from the nozzle. The inventors of the present invention have found that there is. Such a problem is not limited to a liquid ejecting apparatus having both an inflow path for allowing liquid to flow into the liquid chamber and an outflow path for allowing liquid to flow out of the liquid chamber, but also the inner wall surface of the flow path of the liquid connected to the liquid chamber This is a problem common to all liquid ejecting apparatuses having a configuration for displacing the liquid.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

[1] According to the first aspect of the present invention, a liquid ejection device that ejects liquid is provided. The liquid ejection device of this aspect is connected to a nozzle and contains a liquid chamber; a liquid chamber drive unit that changes the volume of the liquid chamber and ejects the liquid from the nozzle; and is connected to the liquid chamber A flow path through which the liquid flows; and by changing the volume of the flow path by displacing the inner wall surface of the flow path, the flow resistance of the flow path is changed, and the liquid chamber and the flow path And a control unit for controlling the liquid chamber driving unit and the valve unit. (I) The amount of change in the volume of the liquid chamber is reduced from the flow path to the liquid chamber due to a decrease in the volume of the flow path as the valve section reduces the volume of the flow path. A first control for increasing the volume of the liquid chamber in the liquid chamber drive unit so as to be equal to or greater than the volume of the liquid flowing in; and (ii) as the volume of the flow path is increased in the valve unit. The volume of the liquid chamber is set in the liquid chamber drive unit so that the amount of change in the volume of the liquid chamber is equal to or greater than the volume of the liquid flowing out from the liquid chamber into the flow path due to the increase in the volume of the flow path. And executing at least one of a second control to be decreased.
According to the liquid ejection device of this aspect, in the first control for decreasing the volume of the flow path in order to increase the flow path resistance of the flow path, at least the flow volume flows into the liquid chamber due to the decrease in the volume of the flow path. The volume of the liquid chamber increases by the amount that can accommodate the liquid to be stored. Therefore, it is possible to prevent the liquid from flowing out from the nozzle due to the decrease in the volume of the flow path. Further, in the second control for increasing the volume of the flow path in order to reduce the flow path resistance of the flow path, at least the volume of the liquid flowing out from the liquid chamber to the flow path due to the increase in the volume of the flow path is liquid. The chamber volume is reduced. Accordingly, it is possible to suppress the outside air from being drawn from the nozzle due to the increase in the volume of the flow path.

[2] In the liquid ejection device according to the above aspect, the flow path includes an inflow path through which the liquid supplied to the liquid chamber flows; the valve section is provided in the inflow path, and the volume of the inflow path is increased. The first control is configured such that the amount of change in the volume of the liquid chamber is reduced by the decrease in the volume of the inflow path as the volume of the inflow path is decreased in the supply valve section. The liquid chamber drive unit includes a first supply valve control for increasing the volume of the liquid chamber so that the volume of the liquid chamber is greater than or equal to the volume of the liquid flowing into the liquid chamber from an inflow path; As the volume of the inflow passage is increased, the amount of change in the volume of the liquid chamber becomes greater than the volume of the liquid flowing out from the liquid chamber into the inflow passage due to the increase in the volume of the inflow passage. And a second supply for reducing the volume of the liquid chamber to the liquid chamber driving unit. It may comprise a control.
According to the liquid ejection device of this aspect, in the first supply valve control for reducing the volume of the inflow path in order to increase the flow path resistance of the inflow path, the liquid is discharged from the nozzle due to the decrease in the volume of the inflow path. Outflow is suppressed. In addition, in the second supply valve control for increasing the volume of the inflow path in order to reduce the flow path resistance of the inflow path, it is suppressed that outside air is drawn from the nozzle due to the increase in the volume of the inflow path. Is done.

[3] In the liquid ejection device according to the above aspect, the liquid chamber includes a first liquid chamber communicating with the first nozzle and a second liquid chamber communicating with the second nozzle; The drive unit includes a first liquid chamber drive unit that changes the volume of the first liquid chamber, and a second liquid chamber drive unit that changes the volume of the second liquid chamber; A first inflow path connected to the first liquid chamber; and a second inflow path connected to the second liquid chamber; and the supply valve section changes a volume of the first inflow path. A first supply valve section; and a second supply valve section that changes a volume of the second inflow passage; and the control section is connected to the first supply valve section in the first control and the second control. As the volume of the second inflow passage is changed by the second supply valve portion while changing the volume of the first inflow passage, While changing the volume of the one liquid chamber, the second liquid chamber driving unit changes the volume of the second liquid chamber; the first supply valve unit and the second supply valve unit have a common driving unit. The volume of the first inflow path and the second inflow path may be changed by the driving force to be generated.
According to the liquid discharge device of this aspect, the drive unit of the first supply valve unit and the second supply valve unit is made common, so the liquid discharge device can be downsized. Further, the operations of the first supply valve portion and the second supply valve portion can be easily synchronized.

[4] In the liquid ejection device of the above aspect, the flow path includes an inflow path through which the liquid supplied to the liquid chamber flows and an outflow path through which the liquid discharged from the liquid chamber flows; The valve portion includes a discharge valve portion that changes a volume of the outflow passage by displacing an inner wall surface of the outflow passage; and the first control is performed by reducing the volume of the outflow passage in the discharge valve portion. The volume of the liquid chamber is set in the liquid chamber driving unit so that the amount of change in the volume of the liquid chamber is equal to or greater than the volume of the liquid flowing into the liquid chamber from the outflow path due to the decrease in the volume of the outflow path. A first discharge valve control for increasing the volume of the outflow passage as the second control increases the volume of the outflow passage in the discharge valve portion. Due to the increase, the volume of the liquid flowing into the liquid chamber from the outflow path becomes more than the volume. As it may comprise a second exhaust valve control for reducing the volume of the liquid chamber to the liquid chamber drive unit.
According to the liquid discharge apparatus of this aspect, in the first discharge valve control for reducing the volume of the outflow path in order to increase the flow path resistance of the outflow path, the liquid is discharged from the nozzle due to the decrease in the volume of the outflow path. Outflow is suppressed. In addition, in the second discharge valve control for increasing the volume of the outflow path in order to reduce the flow path resistance of the outflow path, it is suppressed that outside air is drawn from the nozzle due to the increase in the volume of the outflow path. Is done.

[5] In the liquid discharge apparatus according to the above aspect, the liquid chamber includes a first liquid chamber communicating with the first nozzle and a second liquid chamber communicating with the second nozzle; The drive unit includes a first liquid chamber drive unit that changes the volume of the first liquid chamber, and a second liquid chamber drive unit that changes the volume of the second liquid chamber; A first inflow path connected to the one liquid chamber; and a second inflow path connected to the second liquid chamber; the outflow path being connected to the first liquid chamber. An outflow path and a second outflow path connected to the second liquid chamber; the discharge valve section includes a first discharge valve section that changes a volume of the first outflow path; and the second outflow path A second discharge valve section that changes a volume of the path; and the control section includes a first discharge valve section that is connected to the first discharge path section in the first control and the second control. While changing the volume of the second outflow passage in the second discharge valve section, the second liquid valve driving section changes the volume of the first liquid chamber in accordance with the second discharge valve section. The volume of the second liquid chamber is changed by the liquid chamber driving unit; the first discharge valve unit and the second discharge valve unit are driven by a driving force generated by a common driving unit, The volume of the second outflow path may be changed.
According to the liquid discharge device of this aspect, the drive unit of the first discharge valve portion and the second discharge valve portion is made common, so that the liquid discharge device can be downsized. Further, the operations of the first discharge valve portion and the second discharge valve portion can be easily synchronized.

[6] In the liquid ejection device according to the above aspect, the flow path includes an inflow path through which the liquid supplied to the liquid chamber flows, and an outflow path through which the liquid discharged from the liquid chamber flows; The valve portion is a supply valve portion that changes the volume of the inflow passage by displacing the inner wall surface of the inflow passage, a discharge valve portion that changes the volume of the outflow passage by displacing the inner wall surface of the outflow passage, The first control includes a change amount of the volume of the liquid chamber as the volume of the outflow passage is reduced in the discharge valve portion while the volume of the inflow passage is reduced in the supply valve portion. The liquid chamber drive unit has the liquid chamber so that the volume of the liquid chamber is greater than or equal to the volume of the liquid flowing into the liquid chamber from the inflow path and the outflow path by increasing the volume of the inflow path and the volume of the outflow path. A first valve control for increasing the volume; the second control comprises the supply valve section As the volume of the outflow path is increased in the discharge valve portion while increasing the volume of the inflow path, the amount of change in the volume of the liquid chamber increases as the volume of the inflow path and the volume of the outflow path increase. Therefore, the liquid chamber drive unit may include a second valve control for reducing the volume of the liquid chamber so that the volume of the liquid chamber flows into the liquid chamber from the inflow path and the outflow path.
According to the liquid ejection device of this aspect, in the first valve control for reducing the volume resistance of the inflow path and the outflow path, the liquid is suppressed from flowing out from the nozzle. Further, in the second valve control for increasing the volumes of the inflow passage and the outflow passage in order to reduce the flow resistance, outside air is drawn from the nozzle due to the increase in the volumes of the inflow passage and the outflow passage. Is suppressed.

[7] In the liquid ejection device according to the above aspect, the supply valve unit and the discharge valve unit may change the volume of the outflow path and the volume of the inflow path by a driving force generated by a common drive unit. Good.
According to the liquid ejection device of this aspect, the liquid ejection device can be reduced in size. Further, the operations of the supply valve unit and the discharge valve unit can be easily synchronized.

[8] The liquid ejection device according to the above aspect may further include a circulation path for circulating the liquid discharged to the outflow path to the inflow path.
According to the liquid ejection device of this aspect, it is possible to suppress the retention of the liquid in the liquid chamber, and it is possible to suppress the deterioration of the liquid.

[9] According to the second aspect of the present invention, a liquid chamber communicating with the nozzle and containing the liquid, a liquid chamber driving unit for changing the volume of the liquid chamber and discharging the liquid from the nozzle, The liquid chamber is connected to the liquid chamber, and the flow path of the liquid is changed, and the flow path resistance of the flow path is changed by changing the volume of the flow path by displacing the inner wall surface of the flow path. And a valve unit for controlling the flow of the liquid between the flow path and the flow path. In this form of the control method, (i) the amount of change in the volume of the liquid chamber is reduced from the flow path by decreasing the volume of the flow path as the valve section is reduced in volume of the flow path. A first control for increasing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or larger than the volume of the liquid flowing into the chamber; and (ii) increasing the volume of the flow path in the valve unit. Along with this, the liquid chamber drive unit has the liquid chamber drive unit so that the amount of change in the volume of the liquid chamber is greater than or equal to the volume of the liquid flowing out from the liquid chamber into the flow path due to the increase in the volume of the flow path. A step of executing at least one of a second control for reducing the volume.
According to the control method of this aspect, in the first control in which the volume of the flow path is decreased to increase the flow path resistance of the flow path, the liquid flows out from the nozzle due to the decrease in the volume of the inflow path. Is suppressed. Further, in the second control for increasing the volume of the inflow channel in order to reduce the flow path resistance of the inflow channel, it is suppressed that outside air is drawn from the nozzle due to the increase in the volume of the inflow channel. .

  A plurality of constituent elements of each aspect of the present invention described above are not indispensable, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with a new other component, and partially delete the limited contents of some of the plurality of components. In order to solve part or all of the above-described problems or to achieve part or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  The present invention can also be realized in various forms other than the liquid ejection apparatus and the control method thereof. For example, it is realized in the form of a liquid ejection system, a head provided in the liquid ejection apparatus, a control method of the liquid ejection system and the head, a computer program for realizing such a control method, a non-temporary recording medium on which the computer program is recorded, etc. can do.

1 is a schematic block diagram illustrating a configuration of a liquid ejection device according to a first embodiment. FIG. 3 is a schematic cross-sectional view showing an internal configuration of a head unit in the first embodiment. Explanatory drawing which shows the flow of the discharge control in 1st Embodiment. FIG. 10 is a first schematic diagram illustrating the operation of the head unit in discharge control. FIG. 6 is a second schematic diagram illustrating the operation of the head unit in the discharge control. FIG. 9 is a third schematic diagram illustrating the operation of the head unit in the discharge control. Schematic for demonstrating how to obtain | require a supply side movement volume. Explanatory drawing which shows the flow of the standby control in 1st Embodiment. FIG. 10 is a schematic block diagram illustrating a configuration of a liquid ejection device according to a second embodiment. The schematic sectional drawing which shows the internal structure of the head part in 2nd Embodiment. Explanatory drawing which shows the flow of the discharge control in 2nd Embodiment. FIG. 10 is a first schematic diagram illustrating the operation of the head unit in discharge control. FIG. 6 is a second schematic diagram illustrating the operation of the head unit in the discharge control. FIG. 9 is a third schematic diagram illustrating the operation of the head unit in the discharge control. FIG. 10 is a fourth schematic diagram showing the operation of the head unit in the discharge control. Schematic for demonstrating how to obtain | require the discharge side movement volume. Explanatory drawing which shows the flow of the standby control in 2nd Embodiment. The schematic sectional drawing which shows the internal structure of the head part in 3rd Embodiment. Explanatory drawing which shows the flow of the discharge control in 3rd Embodiment. Explanatory drawing which shows the flow of standby control in 3rd Embodiment. FIG. 10 is a schematic cross-sectional view showing an internal configuration of a head unit in a fourth embodiment. The schematic perspective view which represented typically the internal structure of the head part in 4th Embodiment. Explanatory drawing which shows the flow of the discharge control of 4th Embodiment. Explanatory drawing which shows the timing chart in the discharge control of 4th Embodiment. Schematic for demonstrating how to obtain | require a movement volume. Explanatory drawing which shows the flow of standby control of 4th Embodiment. The 1st schematic perspective view which represented typically the internal structure of the head part of 5th Embodiment. The 2nd schematic perspective view which represented typically the internal structure of the head part of 5th Embodiment. The schematic perspective view which represented typically the internal structure of the head part of 6th Embodiment. Schematic which shows the flow of the discharge control of 7th Embodiment. FIG. 10 is a first schematic diagram illustrating the operation of the head unit in discharge control. FIG. 6 is a second schematic diagram illustrating the operation of the head unit in the discharge control. FIG. 9 is a third schematic diagram illustrating the operation of the head unit in the discharge control.

A. First embodiment:
FIG. 1 is a schematic block diagram illustrating the overall configuration of a liquid ejection apparatus 100A according to the first embodiment. The liquid ejection apparatus 100A includes a tank 10, a pressure adjustment unit 15, a supply path 30, a head unit 40A, and a control unit 80.

  The tank 10 contains a liquid. As the liquid, for example, ink having a predetermined viscosity is accommodated. The liquid in the tank 10 is supplied to the head unit 40A through the supply path 30 connected to the head unit 40A.

  A pressure adjusting unit 15 is provided in the supply path 30. The pressure adjusting unit 15 adjusts the pressure of the liquid supplied to the head unit 40A to a predetermined pressure. The head unit 40A is configured by a pump that sucks liquid from the tank 10, a valve that opens and closes so that the pressure on the head unit 40A side becomes a predetermined pressure, and the like (not shown). The liquid supplied to the head unit 40A is discharged by the head unit 40A. The operation of the head unit 40A is controlled by the control unit 80. The configuration of the head unit 40A will be described later.

  The control unit 80 is configured as a computer including a CPU and a memory, and implements various functions for controlling the liquid ejection apparatus 100A by executing a control program stored in the memory. The control program may be recorded on various tangible recording media that are not temporary.

  FIG. 2 is a schematic cross-sectional view showing the internal configuration of the head portion 40A. FIG. 2 schematically illustrates the configuration of the head portion 40 </ b> A on a cut surface passing through the central axis of the nozzle 41 and the inflow path 31. The head unit 40 </ b> A includes a nozzle 41 that discharges the liquid LQ, and a liquid chamber 42 that communicates with the nozzle 41.

  The liquid chamber 42 is a room to which the liquid LQ is supplied. The liquid chamber 42 is configured as an internal space of a metal casing. The nozzle 41 is provided as a through hole that opens in the bottom surface 42 e of the liquid chamber 42. In the present embodiment, the nozzle 41 is open in the direction of gravity. The head unit 40A may include two or more nozzles 41 and two liquid chambers 42.

  A liquid chamber drive unit 43 is provided in the liquid chamber 42. The liquid chamber driving unit 43 changes the volume of the liquid chamber 42 under the control of the control unit 80 (FIG. 1), and generates a driving force for discharging the liquid LQ from the nozzle 41. The top surface 45, which is the upper surface of the liquid chamber 42, is configured as a diaphragm (diaphragm) by a deformable member such as a metal thin film member or elastic rubber. The liquid chamber driving unit 43 is connected to the upper portion of the top surface 45, and by applying an external force to the top surface 45 to bend and deform it, the top surface 45 is displaced in the vertical direction to increase the volume of the liquid chamber 42. change. In the present embodiment, the liquid chamber drive unit 43 is configured by a piezo actuator that can expand and contract in the vertical direction. The operation of the liquid chamber drive unit 43 that discharges the liquid LQ from the nozzle 41 will be described later.

  Inside the head portion 40A, an inflow path 31 is provided that connects the supply path 30 (FIG. 1) and the liquid chamber 42 and flows the liquid LQ supplied from the supply path 30 into the liquid chamber 42. ing. A supply valve portion 33 is provided in the inflow passage 31. The supply valve unit 33 changes the volume of the inflow channel 31 and changes the flow resistance of the inflow channel 31 under the control of the control unit 80, thereby causing the liquid LQ between the liquid chamber 42 and the inflow channel 31. To control the flow.

  The supply valve unit 33 includes a flow path wall member 34 and a drive unit 35. The flow path wall member 34 constitutes a part of the inner wall surface of the inflow path 31. The flow path wall member 34 is configured by a member capable of bending deformation such as a metal thin film or elastic rubber. In the present embodiment, the flow path wall member 34 is disposed on the upper surface side of the inflow path 31 so as to bend and deform in the vertical direction. The drive unit 35 is connected to the flow path wall member 34, and applies an external force to the flow path wall member 34 to bend and deform the flow path wall member 34 under the control of the control unit 80. In the present embodiment, the drive unit 35 is configured by a piezo actuator that can expand and contract in the vertical direction.

  When the drive part 35 expands and contracts and the supply valve part 33 is bent and deformed, the flow path cross-sectional area of the inflow path 31 in the portion where the supply valve part 33 is provided changes, and the flow path resistance of the inflow path 31 changes. Changes. In this embodiment, the supply valve part 33 can bend and deform | transform until the flow-path wall member 34 contacts the opposing inner wall surface, and can block | interrupt the inflow path 31 on the way. The supply valve unit 33 only needs to increase or decrease the flow path resistance of the inflow path 31, and may not be able to completely block the inflow path 31.

  With reference to FIG. 3, FIG. 4A-FIG. 4C, and FIG. 5, an example of the discharge control of the head part 40A which the control part 80 (FIG. 1) performs is demonstrated. FIG. 3 is an explanatory diagram showing a flow of discharge control. 4A to 4C are schematic diagrams illustrating the operation of the head unit 40A in each control process in the discharge control.

  The control unit 80 sets the head unit 40A to an initial state before executing the discharge control. In this initial state, the pressure adjusting unit 15 adjusts the internal pressure of the liquid chamber 42 to a predetermined reference pressure that is equal to or lower than the meniscus pressure resistance of the nozzle 41. The control unit 80 sets the volume of the liquid chamber 42 to a predetermined reference volume, and sets the volume of the inflow passage 31 to a predetermined reference volume. The reference volume of the liquid chamber 42 may be the volume of the liquid chamber 42 when the voltage for expansion and contraction is not applied to the liquid chamber driving unit 43 and the top surface 45 is not bent and deformed. Similarly, the reference volume of the inflow path 31 is the volume of the inflow path 31 when no voltage for expansion and contraction is applied to the drive unit 35 of the supply valve unit 33 and the flow path wall member 34 is not bent and deformed. Also good. Hereinafter, the flow path resistance of the inflow path 31 at the reference volume is also referred to as “reference resistance”.

  Step S <b> 10 is a process for preparing to start discharging the liquid LQ from the nozzle 41. In step S10, the control unit 80 decreases the volume of the inflow channel 31 and increases the volume of the liquid chamber 42 from the reference volume while increasing the flow resistance of the inflow channel 31 from the reference resistance (FIG. 4A). In the present embodiment, in step S10, the control unit 80 reduces the volume of the inflow channel 31 to a predetermined minimum volume. The minimum volume may be a volume at which the above-described inflow path 31 is blocked.

Here, the direction of increasing the variation [Delta] V _R of the volume of the liquid chamber 42 in step S10, the volume of the liquid LQ flowing from the inflow passage 31 into the liquid chamber 42 by the supply valve 33 to vary the volume of the inlet channel 31 The amount is equal to or greater than V _A (ΔV _R ≧ V _A ). The volume _VA corresponds to the amount of the liquid LQ that is pushed out from the inflow path 31 to the liquid chamber 42 as the supply valve portion 33 decreases the volume of the inflow path 31. Further, the supply valve portion 33 increases the volume of the inflow passage 31, which corresponds to the amount of liquid LQ that is drawn from the liquid chamber 42 into the inflow passage 31. Hereinafter, the volume V _{A of the} liquid LQ is also referred to as “supply side moving volume V _A ”. _A method of obtaining the supply side moving volume _VA will be described later.

In step S10, by increasing the volume of the amount of change [Delta] V _R in the liquid chamber 42, at least, a buffer space that can accept the liquid LQ of the supply-side movement volume V _A is formed in the liquid chamber 42. Therefore, leakage of the liquid LQ from the nozzle 41 due to the liquid LQ pushed out to the liquid chamber 42 by the operation of the supply valve portion 33 in the direction of closing the inflow path 31 is suppressed.

Variation [Delta] V _R of the volume of the liquid chamber 42 in step S10, in order to suppress the outside air entering from the nozzle 41, is the state in which the meniscus is formed in the nozzle 41 is set in a range that is maintained desirable. Further, the change amount [Delta] V _R of the volume of the liquid chamber 42, the supply-side movement volume V _A, be a value obtained by adding the volume of the liquid LQ in accordance with the discharge amount of the liquid LQ from the nozzle 41 in the following steps Good.

  Step S13 is a step of starting the discharge of the liquid LQ from the nozzle 41. In step S <b> 13, the control unit 80 rapidly expands the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42 (FIG. 4B). As a result, the liquid LQ is pushed out from the liquid chamber 42, and the liquid LQ starts to be ejected from the nozzle 41. At this time, since the flow path resistance of the inflow path 31 is increased in step S10, the pressure of the liquid chamber 42 for discharging the liquid LQ is prevented from escaping to the inflow path 31 side.

  Step S16 is a step for separating the liquid LQ discharged from the nozzle 41 as the droplet DR. In step S <b> 16, the control unit 80 reduces the pressure of the liquid chamber 42 by contracting the liquid chamber driving unit 43 while the liquid LQ is being discharged from the nozzle 41 and expanding the volume of the liquid chamber 42. (FIG. 4C). As a result, a suction force that pulls back the liquid LQ from the nozzle 41 to the liquid chamber 42 is generated, and the liquid LQ ejected outside the nozzle 41 can be separated as a droplet DR from the liquid LQ of the nozzle 41 and caused to fly. .

  In step S <b> 16, the control unit 80 gradually increases the volume of the inflow path 31 by the supply valve unit 33, returns the volume of the inflow path 31 to the reference volume, and sets the flow path resistance of the inflow path 31 as the reference resistance. It is desirable that the increase rate of the volume of the inflow passage 31 is appropriately adjusted according to the increase rate of the volume of the liquid chamber 42. The increasing speed of the volume of the inflow passage 31 is desirably adjusted so that the above-described suction force for separating the droplet DR does not become too small and does not become so large that outside air is sucked from the nozzle 41. .

FIG. 5 is a schematic diagram for explaining how to determine the supply side moving volume _VA . The supply side moving volume _VA can be obtained as follows. The inflow path 31 and the liquid chamber 42 are filled with the liquid LQ, the head portion 40A is set to the initial state described above, and the position of the meniscus at the nozzle 41 at this time is recorded. And without changing the volume of the liquid chamber 42 to the liquid chamber drive part 43, the volume of the inflow path 31 is reduced to the minimum volume by the supply valve part 33, and the liquid LQ from the position of the meniscus in the initial state is reduced. Find the increase. This increase amount corresponds to the supply side moving volume _VA . The supply side moving volume _VA may be obtained as a decrease amount of the liquid LQ in the liquid chamber 42 and the nozzle 41 when the volume of the inflow passage 31 is returned from the minimum volume to the reference volume.

  With reference to FIG. 6, an example of the standby control of the head unit 40A executed by the control unit 80 (FIG. 1) will be described. FIG. 6 is an explanatory diagram showing a flow of standby control. In step S20, the control unit 80 determines whether or not to put the head unit 40A in a standby state. The control unit 80 determines that the head unit 40A is in a standby state when the discharge control of the liquid LQ is not executed for a predetermined period (for example, about several minutes to several hours). The control unit 80 may determine that the head unit 40A is to be put into a standby state when receiving an operation for putting the head unit 40A into a standby state by a user of the liquid ejection apparatus 100A.

When it is determined that the head unit 40A is set to the standby state, the control unit 80 executes the process of step S22. In step S22, the control unit 80 reduces the volume of the inflow path 31 to the supply valve unit 33 while reducing the volume of the inflow passage 31 in the same manner as in step S10 (FIGS. 3 and 4A) in the discharge control. Is increased to bring the head portion 40A into a standby state. The change amount [Delta] V _R of the volume of the liquid chamber 42 in step S22, as not to cause wasting pressure change in the liquid chamber 42, to be the following values variation [Delta] V _R at step S10 ejection control desirable. Further, in step S22, it is desirable that the inflow path 31 is substantially blocked by the supply valve portion 33.

  In step S <b> 22, the volume of the liquid chamber 42 increases with the closing operation of the supply valve unit 33, and thus the liquid LQ leaks from the nozzle 41 due to the liquid LQ pushed out from the inflow path 31. Is suppressed. Further, in the standby state, the supply valve portion 33 is in a state in which the inflow of the liquid LQ from the upstream side of the supply valve portion 33 is suppressed, so that the liquid LQ leaks accidentally from the nozzle 41 during the standby state. Is suppressed.

The control unit 80 maintains this standby state until a discharge control execution command is issued or until a standby state canceling operation by the user is received (step S25). When canceling the standby state, the control unit 80 executes the process of step S26. In step S <b> 26, the control unit 80 causes the liquid valve driving unit 43 to decrease the volume of the liquid chamber 42 while causing the supply valve unit 33 to perform a valve opening operation that increases the volume of the inflow passage 31. Return to the reference volume. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S26 as in step S22, a supply-side moving volume _{V A} or more.

  In step S26, in order to reduce the volume of the liquid chamber 42 while performing the valve opening operation of the supply valve section 33, the force of drawing the liquid LQ into the inflow path 31 generated immediately after the volume of the inflow path 31 starts to increase. This prevents the outside air from being sucked from the nozzle 41. In step S <b> 26, the supply valve unit 33 is opened to complete the standby control in the liquid ejection apparatus 100 </ b> A.

In the control of the head portion 40A by the controller 80, as in the above step S10, S22, such that the change amount [Delta] V _R of the volume of the liquid chamber 42 becomes equal to or higher than the supply-side moving volume _{V A,} the volume of the inlet channel 31 Control for increasing the volume of the liquid chamber 42 while decreasing the pressure is referred to as “first supply valve control” (FIGS. 3 and 6). Also, as in the above step S26, so that the variation [Delta] V _R of the volume of the liquid chamber 42 becomes equal to or higher than the supply-side moving volume V _A, while increasing the volume of the inflow channel 31, reducing the volume of the liquid chamber 42 This control is referred to as “second supply valve control” (FIG. 6).

  According to the liquid ejection device 100A of the present embodiment, the first supply valve control suppresses the liquid LQ from leaking from the nozzle 41 due to the valve closing operation of the supply valve unit 33. Further, the second supply valve control suppresses the outside air from entering the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the supply valve portion 33. In addition, according to the liquid ejection apparatus 100A and the control method thereof according to the first embodiment, various functions and effects described in the first embodiment can be achieved.

B. Second embodiment:
FIG. 7 is a schematic block diagram showing the overall configuration of the liquid ejection apparatus 100B in the second embodiment. The liquid ejection device 100B of the second embodiment has substantially the same configuration as the liquid ejection device 100A (FIG. 1) of the first embodiment except for the points described below. The liquid ejection apparatus 100B includes a pressurizing pump 20 instead of the pressure adjusting unit 15, and includes a head unit 40B instead of the head unit 40A. Further, in the liquid ejection device 100B, a discharge path 50, a liquid storage section 70, a negative pressure generation source 75, and a circulation path 90 are further added.

  The pressurizing pump 20 supplies the liquid in the tank 10 to the head unit 40 </ b> B through the supply path 30. The configuration, operation, and control method of the head unit 40B of the second embodiment will be described later. The discharge path 50 connects the head unit 40 </ b> B and the liquid storage unit 70. The liquid that has not been ejected by the head part 40 </ b> B is discharged to the liquid storage part 70 through the discharge path 50. A negative pressure generation source 75 is connected to the liquid storage unit 70. The negative pressure generation source 75 draws liquid from the head unit 40 </ b> B through the discharge path 50 by setting the inside of the liquid storage unit 70 to a negative pressure. The negative pressure generation source 75 is constituted by various pumps.

  In the liquid ejection device 100B, the pressurization pump 20 and the negative pressure generation source 75 function as a liquid supply unit that generates a differential pressure in the supply path 30 and the discharge path 50 and supplies the liquid to the head unit 40B. Note that either the pressurizing pump 20 or the negative pressure generating source 75 may be omitted, and the liquid supply unit may be configured by either the pressurizing pump 20 or the negative pressure generating source 75 alone. In the liquid ejecting apparatus 100B, the liquid that has not been ejected is discharged from the head unit 40B, and therefore, in the head unit 40B, such as sedimentation of sediment components in the liquid in the head unit 40B and changes in the liquid concentration accompanying liquid evaporation Deterioration of the liquid caused by the liquid retention is suppressed.

  The circulation path 90 connects the liquid storage unit 70 and the tank 10. The liquid discharged from the head section 40B through the discharge path 50 and stored in the liquid storage section 70 is returned to the tank 10 through the circulation path 90, and is again supplied to the head section 40B by the pressure pump 20. The circulation path 90 may be provided with a pump for sucking liquid from the liquid reservoir 70. In the liquid ejection apparatus 100B, a configuration in which the circulation path 90 is omitted and the liquid is not circulated may be applied.

  FIG. 8 is a schematic cross-sectional view showing the internal configuration of the head portion 40B. FIG. 8 schematically illustrates the configuration of the head portion 40 </ b> B on a cut surface passing through the central axis of the nozzle 41, the inflow path 31, and the outflow path 51. The configuration of the head portion 40B of the second embodiment is the same as that of the first embodiment except that the supply valve portion 33 of the inflow passage 31 is omitted and an outflow passage 51 and a discharge valve portion 53 are added. The configuration is almost the same as that of the portion 40A (FIG. 2). The head unit 40B may include two or more nozzles 41 and two liquid chambers 42, similarly to the head unit 40A of the first embodiment.

  The outflow path 51 is a flow path that connects the discharge path 50 (FIG. 7) and the liquid chamber 42 and through which the liquid LQ discharged from the liquid chamber 42 flows. The outflow path 51 is provided inside the head portion 40B. In the outflow passage 51, a discharge valve portion 53 is provided. The discharge valve unit 53 changes the volume of the outflow channel 51 and changes the flow resistance of the outflow channel 51 under the control of the control unit 80 (FIG. 7). The flow of the liquid LQ in between is controlled.

  The discharge valve unit 53 includes a flow path wall member 54 and a drive unit 55. The flow path wall member 54 constitutes a part of the inner wall surface of the outflow path 51. The flow path wall member 54 is formed of a member capable of bending deformation such as a metal thin film or elastic rubber. The flow path wall member 54 is disposed so as to bend and deform in the vertical direction on the upper surface side of the outflow path 51. The drive unit 55 is connected to the flow path wall member 54 and applies an external force to the flow path wall member 54 to bend and deform the flow path wall member 54 under the control of the control unit 80 (FIG. 7). The drive unit 55 is configured by a piezo actuator that can expand and contract in the vertical direction.

  When the drive unit 55 expands and contracts and the flow path wall member 54 is bent and deformed, the flow path cross-sectional area of the outflow path 51 at the portion where the flow path wall member 54 is provided changes, and the flow of the outflow path 51 changes. Road resistance changes. The discharge valve portion 53 can bend and deform the flow path wall member 54 until it comes into contact with the opposing inner wall surface, and can block the outflow passage 51 halfway. In addition, the discharge valve part 53 should just be able to increase / decrease the flow-path resistance of the outflow path 51, and does not need to interrupt | block the outflow path 51 completely.

  With reference to FIG. 9, FIG. 10A-FIG. 10D, and FIG. 11, an example of the discharge control of the head part 40B which the control part 80 performs is demonstrated. FIG. 9 is an explanatory diagram illustrating a flow of discharge control according to the second embodiment. 10A to 10D are schematic views illustrating the operation of the head unit 40B in each control process.

  The control unit 80 sets the head unit 40B to an initial state before executing the discharge control. In this initial state, the control unit 80 prevents the liquid LQ from leaking from the nozzle 41 so that the internal pressure of the liquid chamber 42 becomes a predetermined reference pressure equal to or lower than the meniscus pressure resistance of the nozzle 41. The inflow amount and outflow amount of the liquid LQ are adjusted. Further, the control unit 80 sets the volume of the liquid chamber 42 to a predetermined reference volume, and sets the volume of the outflow passage 51 to a predetermined reference volume. As in the first embodiment, the reference volume of the liquid chamber 42 is the volume of the liquid chamber 42 when the voltage for expansion and contraction is not applied to the liquid chamber drive unit 43 and the top surface 45 is not bent and deformed. Also good. Further, the reference volume of the outflow passage 51 is also the volume of the outflow passage 51 when no voltage for expansion and contraction is applied to the drive portion 55 of the discharge valve portion 53 and the flow path wall member 54 is not bent and deformed. Good. Hereinafter, the flow path resistance of the outflow path 51 at the reference volume is also referred to as “reference flow path resistance”.

  Step S <b> 30 is a process for preparing to start discharging the liquid LQ from the nozzle 41. In step S30, the control unit 80 increases the volume of the liquid chamber 42 from the reference volume while decreasing the volume of the outflow path 51 and increasing the flow path resistance of the outflow path 51 from the reference resistance (FIG. 10A). The control unit 80 reduces the volume of the outflow passage 51 to a predetermined minimum volume. The minimum volume may be a volume at which the above-described outflow passage 51 is blocked.

Here, the direction of increasing the variation [Delta] V _R of the volume of the liquid chamber 42 in step S30, the volume of the liquid LQ flowing into the liquid chamber 42 from the outlet passage 51 by the discharge valve unit 53 to vary the volume of the outlet channel 51 The amount is equal to or greater than V _B (ΔV _R ≧ V _B ). This volume V _B corresponds to the amount of liquid LQ that is pushed out from the outflow path 51 to the liquid chamber 42 by the discharge valve portion 53 reducing the volume of the outflow path 51. Further, the discharge valve portion 53 increases the volume of the outflow passage 51, which corresponds to the amount of liquid LQ that is drawn from the liquid chamber 42 into the outflow passage 51. Hereinafter, the volume V _{B of the} liquid LQ is also referred to as “discharge side moving volume V _B ”. It will be described later how to obtain the discharge side movable volume V _B.

In step S30, by increasing the volume of the amount of change [Delta] V _R in the liquid chamber 42, at least, a buffer space that can accommodate the liquid LQ corresponding to the discharge-side moving volume V _B is formed in the liquid chamber 42. Therefore, the leakage of the liquid LQ from the nozzle 41 due to the liquid LQ pushed into the liquid chamber 42 by the operation of the discharge valve portion 53 in the direction of closing the outflow passage 51 is suppressed.

Variation [Delta] V _R of the volume of the liquid chamber 42 in step S30, in order to suppress the outside air entering from the nozzle 41, is the state in which the meniscus is formed in the nozzle 41 is set in a range that is maintained desirable. Variation [Delta] V _R of the volume of the liquid chamber 42, the discharge-side moving volume V _B, may be a value obtained by adding the liquid LQ of the volume corresponding to the discharge amount of the liquid LQ from the nozzle 41 in the following steps.

  Step S33 is a step of starting the discharge of the liquid LQ from the nozzle 41. In step S33, the control unit 80 rapidly expands the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42 (FIG. 10B). As a result, the liquid LQ is pushed out from the liquid chamber 42, and the liquid LQ starts to be ejected from the nozzle 41. At this time, since the flow path resistance of the outflow passage 51 is increased in step S30, the pressure of the liquid chamber 42 for discharging the liquid LQ is prevented from escaping to the outflow passage 51 side.

  Step S36 is a process for separating the liquid LQ discharged from the nozzle 41 as the droplet DR. In step S36, the control unit 80 reduces the pressure of the liquid chamber 42 by contracting the liquid chamber driving unit 43 and expanding the volume of the liquid chamber 42 while the liquid LQ is being discharged from the nozzle 41. (FIG. 10C). As a result, a force for pulling back the liquid LQ from the nozzle 41 to the liquid chamber 42 is generated, and the liquid LQ discharged to the outside of the nozzle 41 can be separated as a droplet DR from the liquid LQ of the nozzle 41 so as to fly.

In step S36, the control unit 80 makes the volume of the liquid chamber 42 larger than the reference volume in preparation for the valve opening operation of the discharge valve unit 53 in step S38. Control unit 80, by the amount corresponding to the change amount [Delta] V _R of the volume of the liquid chamber 42 in step S38 described below, is preferably larger than the reference volume to the volume of the liquid chamber 42.

  In step S <b> 38, the control unit 80 causes the liquid chamber driving unit 43 to decrease the volume of the liquid chamber 42 while causing the discharge valve unit 53 to open the valve to increase the volume of the outflow passage 51. To the reference volume (FIG. 10D). In step S38, the control unit 80 increases the volume of the outflow path 51 to the reference volume, and sets the flow path resistance of the outflow path 51 to the reference resistance.

Variation [Delta] V _R of the volume of the liquid chamber 42 in step S38 as in step S30, a discharge-side moving volume _{V B} or more. In step S38, the volume of the liquid chamber 42 is decreased while performing the valve opening operation of the discharge valve section 53, so that the liquid LQ is drawn into the discharge valve section 53 caused by the increase in the volume of the outflow passage 51. In addition, the outside air is prevented from being sucked into the liquid chamber 42 from the nozzle 41.

Figure 11 is a schematic diagram for explaining how to determine the discharge side movable volume V _B. The discharge side moving volume V _B can be obtained as follows. The inflow path 31, the outflow path 51, and the liquid chamber 42 are filled with the liquid LQ, and the head portion 40B is set to the initial state described above, and the position of the meniscus at the nozzle 41 at this time is recorded. And without changing the volume of the liquid chamber 42 to the liquid chamber drive part 43, the volume of the outflow path 51 is reduced to the minimum volume by the discharge valve part 53, and the liquid LQ from the position of the meniscus in the initial state is reduced. Find the increase. This increase amount corresponds to the discharge side movement volume V _B. The discharge side moving volume V _B may be obtained as a decrease amount of the liquid LQ in the liquid chamber 42 and the nozzle 41 when the volume of the outflow passage 51 is returned from the minimum volume to the reference volume.

  With reference to FIG. 12, an example of the standby control of the head unit 40B executed by the control unit 80 (FIG. 7) will be described. FIG. 12 is an explanatory diagram illustrating a flow of standby control according to the second embodiment. The flow of standby control of the second embodiment is the same as that of the first embodiment except that steps S23 and S27 for driving the discharge valve portion 53 are provided instead of steps S22 and S26 for driving the supply valve portion 33. This is the same as the standby control flow (FIG. 6).

When determining that the head unit 40B is set to the standby state in step S20, the control unit 80 executes the process of step S23. In step S23, the control unit 80 reduces the volume of the outflow passage 51 in the discharge valve unit 53 while reducing the volume of the liquid chamber 42 by the liquid chamber driving unit 43, as in step S30 (FIGS. 9 and 10A) in the discharge control. Is increased to bring the head portion 40B into a standby state. In step S23, the volume of the liquid chamber 42 increases with the valve closing operation of the discharge valve portion 53, and therefore the liquid LQ leaks from the nozzle 41 due to the liquid LQ pushed out from the outflow passage 51. Is suppressed. The change amount [Delta] V _R of the volume of the liquid chamber 42 in step S23, as not to cause wasting pressure change in the liquid chamber 42, to be the following values variation [Delta] V _R at step S30 ejection control desirable. In step S23, it is desirable that the outflow passage 51 is substantially blocked by the discharge valve portion 53.

When canceling the standby state, the control unit 80 executes the process of step S27. In step S27, the controller 80 drives the liquid chamber while performing the valve opening operation for increasing the volume of the outflow passage 51 in the discharge valve portion 53, as in step S38 (FIGS. 9 and 10D) in the discharge control. The volume of the liquid chamber 42 is decreased in the portion 43 to return the volume of the liquid chamber 42 to the reference volume. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S27, similarly to step S23, a discharge-side moving volume _{V B} or more. In step S <b> 27, similarly to step S <b> 38 in the discharge control, the outside air is suppressed from being sucked from the nozzle 41 with the valve opening operation of the discharge valve portion 53.

In the control of the head unit 40B by the control unit 80, as in the above step S30, S23, such that the change amount [Delta] V _R of the volume of the liquid chamber 42 becomes equal to or higher than the discharge-side moving volume _{V B,} the volume of the outlet channel 51 Control for increasing the volume of the liquid chamber 42 while decreasing the pressure is referred to as “first discharge valve control” (FIGS. 9 and 12). Also, as in the above step S38, S27, so that the variation [Delta] V _R of the volume of the liquid chamber 42 becomes equal to or higher than the discharge-side moving volume V _B, while increasing the volume of the outlet channel 51, the volume of the liquid chamber 42 The control for reducing the value is called “second discharge valve control” (FIGS. 9 and 12).

  According to the liquid ejection device 100B of the second embodiment, the first discharge valve control prevents the liquid LQ from leaking from the nozzle 41 due to the valve closing operation of the discharge valve portion 53. Further, the second discharge valve control suppresses the outside air from entering the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the discharge valve portion 53. In addition, according to the liquid ejection device 100B and the control method thereof according to the second embodiment, various functions and effects similar to those described in the first embodiment and the second embodiment can be obtained.

C. Third embodiment:
FIG. 13 is a schematic cross-sectional view illustrating an internal configuration of a head unit 40C included in the liquid ejection device according to the third embodiment. FIG. 13 schematically illustrates the configuration of the head portion 40 </ b> C on a cut surface passing through the central axis of the nozzle 41, the inflow path 31, and the outflow path 51.

  The liquid ejection device according to the third embodiment has the configuration of the liquid ejection device 100B according to the second embodiment except that the head portion 40C according to the third embodiment is provided instead of the head portion 40B according to the second embodiment (see FIG. It is almost the same as FIG. The head portion 40C of the third embodiment is substantially the same as the configuration of the head portion 40B of the second embodiment (FIG. 8) except that the supply valve portion 33 described in the first embodiment is provided in the inflow passage 31. The same. The head unit 40C may include two or more nozzles 41 and two liquid chambers 42, respectively.

  With reference to FIG. 14, an example of ejection control of the head unit 40C executed by the control unit 80 (FIG. 7) in the liquid ejection apparatus of the third embodiment will be described. FIG. 14 is an explanatory diagram showing a flow of discharge control. In the discharge control of the third embodiment, the discharge control of the first embodiment (FIG. 3) and the discharge control of the second embodiment (FIG. 9) are combined.

Step S40 is the first supply valve control described in the first embodiment. In step S40, as in step S10 (FIG. 3) described in the first embodiment, the control unit 80 decreases the volume of the inflow path 31 and increases the flow path resistance of the inflow path 31 from the reference resistance. The volume of the liquid chamber 42 is expanded from the reference volume. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S40 is the amount of the supply-side movement volume _{V A} (FIG. 5) or more as described in the first embodiment (ΔV _R ≧ _V A). As a result, the liquid LQ is prevented from leaking from the nozzle 41 in accordance with the valve closing operation of the supply valve unit 33.

Step S42 is the first discharge valve control described in the second embodiment. In step S42, as in step S30 (FIG. 9) described in the second embodiment, the control unit 80 decreases the volume of the outflow path 51 and increases the flow path resistance of the outflow path 51 from the reference resistance. The volume of the liquid chamber 42 is increased. In step S42, the volume of the liquid chamber 42 is further increased from the volume increased in step S40. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S42 is the amount of discharge-side moving volume _{V B} (Fig. 11) or described in the second embodiment (ΔV _R ≧ _V A). As a result, leakage of the liquid LQ from the nozzle 41 due to the valve closing operation of the discharge valve portion 53 is suppressed.

  In step S45, as in step S13 (FIG. 3) of the first embodiment, the control unit 80 abruptly extends the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42. As a result, the liquid LQ is pushed out from the liquid chamber 42, and the liquid LQ starts to be ejected from the nozzle 41. At this time, since the flow path resistance of the inflow path 31 and the outflow path 51 is increased in steps S40 and S42, the pressure of the liquid chamber 42 for discharging the liquid LQ escapes to the inflow path 31 and the outflow path 51. Is suppressed.

  In step S <b> 46, the control unit 80 increases the volume of the liquid chamber 42 while the liquid LQ is being discharged from the nozzle 41, and generates a suction force that pulls the liquid LQ back from the nozzle 41 to the liquid chamber 42. Thereby, the liquid LQ discharged outside the nozzle 41 is separated from the liquid LQ of the nozzle 41 and flies as a droplet DR. The control unit 80 gradually increases the volume of the inflow path 31 to the reference volume, and returns the flow path resistance of the inflow path 31 to the reference resistance. The control unit 80 increases the volume of the liquid chamber 42 from the reference volume while changing the volume of the inflow passage 31.

Step S48 is the second discharge valve control described in the second embodiment. In step S48, as in step S38 (FIG. 9) described in the second embodiment, the control unit 80 causes the discharge valve unit 53 to perform a valve opening operation to increase the volume of the outflow passage 51 to the reference volume. The liquid chamber drive unit 43 reduces the volume of the liquid chamber 42 to return the volume of the liquid chamber 42 to the reference volume. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S48 is the discharge side moves the volume V _{B (Fig.} 11) or more of the values described in the second embodiment. Accordingly, it is possible to suppress the outside air from being sucked into the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the supply valve portion 33.

  With reference to FIG. 15, an example of standby control of the head unit 40 </ b> C executed by the control unit 80 in the liquid ejection apparatus of the third embodiment will be described. FIG. 15 is an explanatory diagram illustrating a flow of standby control according to the third embodiment. In the discharge control of the third embodiment, standby control (FIG. 6) of the first embodiment and standby control (FIG. 12) of the second embodiment are combined.

  In the control flow of the third embodiment, when it is determined in step S20 that the head unit 40C is set to the standby state, the control unit 80 sequentially executes step S22 and step S23. Step S22 is the first supply valve control described in the first embodiment (FIG. 6). Step S23 is the first discharge valve control described in the second embodiment (FIG. 12). The execution order of step S22 and step S23 may be switched.

  When canceling the standby state of the head unit 40C, the control unit 80 sequentially executes step S26 and step S27. Step S26 is the second supply valve control described in the first embodiment (FIG. 6). Step S27 is the second discharge valve control described in the second embodiment (FIG. 12). The execution order of step S26 and step S27 may be switched.

  According to the liquid ejection device of the third embodiment, the first supply valve control suppresses the liquid LQ from leaking from the nozzle 41 due to the valve closing operation of the supply valve unit 33. Further, the first discharge valve control prevents the liquid LQ from leaking from the nozzle 41 due to the valve closing operation of the discharge valve portion 53. According to the liquid ejection device of the third embodiment, the second supply valve control suppresses the outside air from entering the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the supply valve unit 33. ing. Further, the second discharge valve control suppresses the outside air from entering the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the discharge valve portion 53. In addition, according to the liquid ejection device and the control method thereof according to the third embodiment, various functions and effects similar to those described in the above embodiments can be achieved.

D. Fourth embodiment:
With reference to FIG. 16 and FIG. 17, the structure of the head part 40D with which the liquid discharge apparatus of 4th Embodiment is provided is demonstrated. FIG. 16 is a schematic cross-sectional view showing the internal configuration of the head portion 40D in the fourth embodiment. FIG. 16 schematically illustrates the configuration of the head portion 40 </ b> D on a cut surface passing through the central axis of the nozzle 41, the inflow path 31, and the outflow path 51. FIG. 17 is a schematic perspective view schematically showing the internal configuration of the head unit 40D.

  The configuration of the liquid ejection apparatus of the fourth embodiment is substantially the same as the configuration of the liquid ejection apparatus 100B of the second embodiment (FIG. 7) except that the head section 40D is provided instead of the head section 40B. is there. The configuration of the head unit 40D of the fourth embodiment is the same as that of the third embodiment except that one driving unit 60 is provided instead of the two driving units 35 and 55 and a connecting member 65 is provided. This is almost the same as the configuration of the head portion 40C (FIG. 13).

  The head unit 40D of the fourth embodiment includes a drive unit 60 that is common to the supply valve unit 33 and the discharge valve unit 53. The drive part 60 gives the drive force for changing the volume of the inflow path 31 and the outflow path 51 to the supply valve part 33 and the discharge valve part 53 under control of the control part 80 (FIG. 7). The driving unit 60 applies, as the driving force, an external force that bends and deforms the flow path wall member 34 of the supply valve unit 33 and the flow path wall member 54 of the discharge valve unit 53 via the connecting member 65. The drive unit 60 is configured by a piezo actuator that can be expanded and contracted in the vertical direction, and the flow path wall member 34 and the discharge valve unit of the supply valve unit 33 that are coupled to the coupling member 65 by expanding and contracting in the vertical direction. Both the flow path wall members 54 of 53 are bent up and down and deformed.

  The connecting member 65 has a construction part 66 and two connecting parts 67. The erection portion 66 is configured as a columnar portion that is laid across the supply valve portion 33 and the discharge valve portion 53. The erection unit 66 is disposed above the liquid chamber 42 and the liquid chamber driving unit 43 disposed above the liquid chamber 42. Each connecting portion 67 is configured as a convex portion protruding downward from the erection portion 66. A lower end portion of the first connection portion 67 is connected to the flow path wall member 34 of the supply valve portion 33, and a lower end portion of the second connection portion 67 is connected to the flow path wall member 54 of the discharge valve portion 53. When the drive unit 60 expands and contracts, the connecting member 65 is displaced up and down, and the flow path wall members 34 and 54 are bent and deformed. In the head portion 40D, the cycle of the flow path resistance change in the inflow path 31 and the cycle of the flow path resistance change in the outflow path 51 are synchronized.

With reference to FIG. 18, FIG. 19, and FIG. 20, an example of the discharge control of the head unit 40D executed by the control unit 80 will be described. FIG. 18 is an explanatory diagram illustrating a flow of discharge control according to the fourth embodiment. FIG. 19 is a timing chart showing a change in volume of the liquid chamber 42 and a change in flow path resistance in the discharge control of the fourth embodiment. The horizontal axis in FIG. 19 indicates the elapsed time. The vertical axis on the left side of FIG. 19 indicates the volume change amount that is the change amount of the volume of the liquid chamber 42 from the reference volume. The volume change amount indicates that the larger the value is, the smaller the volume of the liquid chamber 42 is. The volume change amounts ΔV ₁ , ΔV ₂ , ΔV ₃ , ΔV ₄ in FIG. 19 satisfy the relationship of ΔV ₁ <ΔV ₂ <ΔV ₃ <ΔV ₄ . The vertical axis on the right side of FIG. 19 indicates the flow path resistance in the inflow path 31 and the outflow path 51. The greater the value of the flow path resistance, the greater the amount of expansion and deformation of the drive unit 60, and the smaller the volume in the supply valve unit 33 and the discharge valve unit 53. In FIG. 19, the change over time of the volume change amount is illustrated by a solid line graph Ga, and the change over time of the flow path opening is illustrated by a dashed line graph Gb.

The control unit 80 sets the head unit 40D to an initial state before executing the discharge control (FIG. 19). The control unit 80 sets the volume of the liquid chamber 42 to a volume slightly decreased by ΔV ₁ from the reference volume at time t ₀ before starting the discharge of the liquid LQ from the nozzle 41. Further, the flow path resistances of the inflow path 31 and the discharge valve portion 53 are set to the maximum value R1. When the flow path resistance is the maximum value R1, the extension amount of the drive unit 60 is the maximum, and the inflow path 31 and the outflow path 51 are almost blocked.

  Step S50 (FIG. 18) is a step of starting the discharge of the liquid LQ from the nozzle 41. In step S50, the liquid LQ is discharged from the nozzle 41 by decreasing the volume of the liquid chamber 42 while increasing the volumes of the inflow path 31 and the outflow path 51 from the initial state as described below.

Step S50 is executed at times t _{1 to} t ₂ (FIG. 19). From time t _{1 to} t ₂ , the control unit 80 rapidly expands and deforms the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42 by ΔV ₃ from the reference volume, thereby rapidly increasing the pressure of the liquid chamber 42. Increase. Then, liquid starts to be ejected from the nozzle 41 using this pressure as a driving force. On the other hand, the control unit 80 before and after the time t _1, to initiate shrinkage deformation of the driving portion 60, gradually reduce the flow resistance in the inlet channel 31 and outlet channel 51. The change rate of the channel resistance is slower than the change rate of the volume of the liquid chamber 42. Between times t _{1 and} t ₂ , the flow path resistance is still relatively high, so that the pressure of the liquid chamber 42 for discharging the liquid applied by driving the liquid chamber driving unit 43 is the inflow path. Escape from 31 and outflow passage 51 is suppressed.

  Step S52 (FIG. 18) is a step of opening the inflow path 31 and the outflow path 51 while the liquid LQ is being discharged from the nozzle 41. In step S52, as described below, the volumes of the inflow path 31 and the outflow path 51 are further increased, and the volume of the liquid chamber 42 is further decreased.

Step S52 is performed at time _t 2 ~t ₃ (Figure 19). Control unit 80, the time t _2, the reduce the rate at which the liquid chamber drive unit 43 is extended, gradually reducing the volume of the liquid chamber 42 than at time t ₁ ~t _2, at time t _3, The volume of the liquid chamber 42 is reduced to a minimum state by reducing the volume of the liquid chamber 42 by ΔV ₄ from the reference volume. On the other hand, the control unit 80, even after the time t _2, the gradually reducing the flow resistance in the inlet channel 31 and outlet channel 51 continues to shrink deformation of the drive unit 60, before the time t _3, The channel resistance is set to the minimum value R0.

By setting the flow resistance to the minimum value R0 and opening the inflow path 31 and the outflow path 51 between times t _{2 and} t ₃ , the pressure in the liquid chamber 42 can be rapidly reduced, A suction force that pulls the liquid LQ of the nozzle 41 back toward the liquid chamber 42 can be generated. With this suction force, the liquid LQ flowing out from the nozzle 41 can be separated from the liquid LQ in the nozzle 41, and the liquid LQ ejected from the nozzle 41 can fly as droplets.

Variation [Delta] V _R of the volume of the liquid chamber 42 at time _t 2 ~t ₃ is determined as the difference between [Delta] V ₄ and [Delta] V _3. Variation [Delta] V _R of this volume, the inflow channel 31 and outflow channel 51 volume varies with the inflow path 31 and the liquid LQ of the volume to move between each and the liquid chamber 42 of the outlet channel 51 total V _C or more of Quantity (ΔV _R ≧ V _A ). The volume V _C is that by a supply valve 33 and the exhaust valve 53 reduces the volume of the inflow channel 31 and outflow channel 51, the amount of the liquid LQ to be extruded from the inlet passage 31 and outlet passage 51 to the liquid chamber 42 It corresponds to. Further, the supply valve section 33 and the discharge valve section 53 correspond to the amount of liquid LQ that is drawn from the liquid chamber 42 into the inflow path 31 and the outflow path 51 by increasing the volumes of the inflow path 31 and the outflow path 51. Hereinafter, the volume V _{C of the} liquid LQ is also referred to as “movement volume V _C ”. The method of obtaining the moving volume V _C will be described later.

At time _t 2 ~t _3, the volume of the liquid chamber 42, by increasing the mobile volume _{V C} or more variation [Delta] V _R, LQ liquid from the liquid chamber 42 due to the opening operation of each valve portion 33 and 53 Outflow is suppressed. Accordingly, the suction force for sucking the liquid LQ of the nozzle 41 is suppressed from being excessively increased, and the outside air is suppressed from being sucked into the liquid chamber 42 from the nozzle 41.

  Step S54 (FIG. 18) is a step of circulating the liquid LQ in the liquid chamber 42 while contracting the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42 to an intermediate volume. The intermediate volume of the liquid chamber 42 is a predetermined volume between the minimum value and the maximum value of the volume of the liquid chamber 42.

Step S54 is performed at time _t 3 ~t ₅ (Figure 19). From time t _{3 to} t ₄ , the control unit 80 increases the volume of the liquid chamber 42 to an intermediate volume that is decreased by ΔV ₂ from the reference volume. The rate of change of the volume of the liquid chamber 42 at times t _{3 to} t ₄ is a relatively slow speed that can maintain a state in which a meniscus is formed in the nozzle 41 so that the entry of outside air from the nozzle 41 is suppressed. is there. Control unit 80, until time t ₅ before the next ejection timing arrives, to maintain the volume of the liquid chamber 42 to the intermediate volume.

During the time t _{3 to} t ₅ , the control unit 80 keeps the inflow path 31 and the outflow path 51 in an open state where the flow path resistance is the minimum value R0, and the liquid is passed through the circulation path 90 (FIG. 7). The liquid LQ in the chamber 42 is circulated and flowed. This suppresses the liquid LQ from staying and deteriorating before the next discharge.

  Step S56 (FIG. 18) is a step of transitioning the head unit 40D to the initial state for the next ejection. In step S56, while decreasing the volume of the inflow path 31 and the outflow path 51 to the minimum volume, the volume of the liquid chamber 42 is increased to the volume in the initial state described above.

Step S56 is performed at time _t 5 ~t ₆ (Figure 19). Time t ₅ is a timing ejection command is issued, the time t ₆ is the start timing of the next discharge. At time t ₅ , the control unit 80 starts the expansion deformation of the drive unit 60 so that the flow path resistance increases, and the contraction deformation of the liquid chamber drive unit 43 so that the volume of the liquid chamber 42 increases. Start. Control unit 80 at time t _6, to increase the flow resistance of the inlet passage 31 and outlet passage 51 to a maximum value R1, by expanding the volume of the liquid chamber 42 from the reference volume to a volume that was reduced by [Delta] V _1, The head unit 40D is set to the initial state.

Variation [Delta] V _R of the volume of the liquid chamber 42 at time _t 5 ~t ₆ is determined as the difference between [Delta] V ₂ and [Delta] V _1. Variation [Delta] V _R of this volume is the amount of further movement the volume _{V C} described above (ΔV _R ≧ _V C). The change amount [Delta] V _R of the volume of the liquid chamber 42, the movement volume V _C, may be a value obtained by adding the volume of the liquid LQ discharged from the nozzle 41 at the next discharge. The increase in the volume of the amount of change [Delta] V _R in the liquid chamber 42, at least, a buffer space that can accommodate the liquid LQ corresponding to the moving volume V _C is formed in the liquid chamber 42. Therefore, the leakage of the liquid LQ from the nozzle 41 due to the liquid LQ pushed out to the liquid chamber 42 by the valve closing operation of the valve portions 33 and 53 is suppressed.

Figure 20 is a schematic diagram for explaining how to determine the movement the volume V _C. Moving the volume V _C can be obtained as follows. The inflow path 31 and the outflow path 51 are brought into an open state with a minimum flow path resistance. Then, the liquid LQ is circulated under the same conditions as during normal driving of the liquid ejection device, the inflow path 31, the outflow path 51, and the liquid chamber 42 are filled with the liquid LQ, and the position of the meniscus at the nozzle 41 is determined. Record. Thereafter, the volume of the inflow path 31 and the outflow path 51 is reduced to the minimum volume by the supply valve section 33 and the discharge valve section 53 without changing the volume of the liquid chamber 42 by the liquid chamber drive section 43 and recorded. An increase amount of the liquid LQ from the meniscus position is obtained. This increase corresponds to a movement volume V _C. Moving the volume V _C may be calculated as a reduction amount of the liquid LQ in the liquid chamber 42 and nozzle 41 upon reconstitution volume of the inflow passage 31 and outflow passage 51 to the reference volume from the minimum volume.

  With reference to FIG. 21, an example of the standby control of the head unit 40D executed by the control unit 80 will be described. FIG. 21 is an explanatory diagram illustrating a flow of standby control according to the fourth embodiment. The standby control flow of the fourth embodiment is the same as the standby control flow of the second embodiment (FIG. 12) except that steps S24 and S29 are provided instead of steps S22 and S26.

In step S24, the control unit 80 expands and deforms the drive unit 60 to reduce the volume of the inflow path 31 and the outflow path 51 to the minimum volume, and contracts and deforms the liquid chamber drive unit 43, so that the liquid chamber 42 The volume is increased and the head unit 40D is set in a standby state. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S24 is moving volume _{V C} or more as described above. The change amount [Delta] V _R of the volume of the liquid chamber 42 in step S24, as not to cause wasting pressure change in the liquid chamber 42, at a value smaller than the change amount [Delta] V _R at step S56 the discharge control described above It is desirable to be. Further, in step S24, it is desirable that the outflow passage 51 is substantially blocked by the discharge valve portion 53.

By the process of step S24, the head portion 40D is in a state where the inflow path 31 and the outflow path 51 are closed and the inflow / outflow of the liquid LQ from the liquid chamber 42 is suppressed. Leakage is suppressed. Also, the volume of the liquid chamber 42, at least move the volume V _C fraction, to increase, due to the liquid LQ to be extruded from the inlet passage 31 and outlet passage 51 with the valve closing operation of each valve portion 33 and 53, The leakage of the liquid LQ from the nozzle 41 is suppressed.

In step S29, the control unit 80 contracts and deforms the driving unit 60 to increase the volumes of the inflow path 31 and the outflow path 51 to the reference volume, and expands and deforms the liquid chamber driving unit 43. The volume is reduced to the reference volume, and the standby state of the head unit 40D is released. Variation [Delta] V _R of the volume of the liquid chamber 42 in step S29 as in step S24, a movement volume _{V C} or more. Variation [Delta] V _R of the volume in step S29 may be the same value as in the step S27. In step S29, since the volume of the liquid chamber 42 is reduced by at least the moving volume V _C , the outside air is prevented from being sucked from the nozzle 41 as the valve portions 33 and 53 are opened.

In the control of the head unit 40D by control unit 80, as in the above step S56, S24, so that the change amount [Delta] V _R of the volume of the liquid chamber 42 becomes more mobile volume _{V C,} inlet passage 31 and outlet passage 51 The control for increasing the volume of the liquid chamber 42 while reducing the volume of the liquid chamber is referred to as “first valve control” (FIGS. 18 and 21). Also, as in the above step S52, S29, so that the variation [Delta] V _R of the volume of the liquid chamber 42 becomes equal to or higher than mobile volume _{V C,} while increasing the volume of the inflow channel 31 and outflow channel 51, the liquid chamber 42 Control for reducing the volume of the valve is called “second valve control” (FIGS. 18 and 21).

  According to the liquid ejection device of the fourth embodiment, the first valve control suppresses the liquid LQ from leaking from the nozzle 41 due to the valve closing operation of the valve portions 33 and 53. Further, the second valve control suppresses the outside air from entering the liquid chamber 42 from the nozzle 41 due to the valve opening operation of the valve portions 33 and 53. In addition, according to the liquid ejection apparatus and the control method thereof according to the fourth embodiment, various functions and effects similar to those described in the above embodiments can be obtained.

E. Fifth embodiment:
With reference to FIG. 22 and FIG. 23, the structure of the head part 40E with which the liquid discharge apparatus in 5th Embodiment is provided is demonstrated. 22 and 23 are schematic perspective views schematically showing the internal configuration of the head portion 40E. FIG. 22 is an exploded view, and shows a state in which the connecting member 65E is separated for convenience. FIG. 13 shows the state of the head unit 40E during use.

  The configuration of the liquid ejection device of the fifth embodiment is the same as that of the liquid ejection device 100B (FIG. 7) of the second embodiment, except that the head unit 40E of the fifth embodiment is provided instead of the head unit 40A. It is almost the same. The configuration of the head unit 40E of the fifth embodiment is substantially the same as the configuration of the head unit 40D of the fourth embodiment (FIGS. 16 and 17) except for the points described below.

  The head portion 40E includes a nozzle 41 and includes a plurality of liquid chambers 42 to which the inflow path 31 and the outflow path 51 are connected. Each inflow path 31 is provided with a flow path wall member 34 constituting the supply valve portion 33, and each outflow path 51 is provided with a flow path wall member 54 constituting the discharge valve portion 53. The head portion 40E includes a connecting member 65E for transmitting the connecting member 65E to each of the flow path wall members 34 and the flow path wall member 54, which is an external force generated by the drive unit 60 for bending deformation.

  The connecting member 65E according to the fifth embodiment includes a connecting plate 68 provided with a plurality of connecting portions 67. The connecting plate 68 is configured by a plate-like member that covers the flow path wall member 34 of the supply valve section 33 and the flow path wall member 54 of the discharge valve section 53 provided in each liquid chamber 42. It is disposed above the liquid chamber drive unit 43. The plurality of connecting portions 67 protrude downward from the lower surface of the connecting plate 68, and are in contact with and connected to the flow path wall member 34 of each supply valve portion 33 and the flow path wall member 54 of the discharge valve portion 53. . The drive unit 60 is installed on the upper surface of the connecting plate 68. The drive unit 60 is expanded and contracted to displace the flow path wall members 34 and 54 by displacing the connecting member 65E up and down.

  In the liquid ejection apparatus according to the fifth embodiment, the control unit 80 (FIG. 7) performs the same control as described in the fourth embodiment on the head unit 40E. According to the liquid ejection apparatus of the fifth embodiment, it is possible to reduce the size of the head unit 40E as compared with the configuration in which the driving unit 60 is provided for each liquid chamber 42. Moreover, the drive of the several supply valve part 33 and the several discharge valve part 53 can be easily synchronized by the single drive part 60. FIG. In addition, according to the liquid ejection device of the fifth embodiment, the effects of the first valve control and the second valve control described in the fourth embodiment, and various actions similar to those described in the above embodiments. There is an effect.

F. Sixth embodiment:
With reference to FIG. 24, the structure of the head part 40F with which the liquid ejection apparatus in 6th Embodiment is provided is demonstrated. FIG. 24 is a schematic perspective view schematically showing the internal configuration of the head portion 40F of the sixth embodiment. The configuration of the liquid ejection apparatus according to the sixth embodiment is similar to the liquid ejection apparatus 100B according to the second embodiment except that the head section 40F according to the sixth embodiment is provided instead of the head section 40B according to the second embodiment. This is almost the same as the configuration (FIG. 7). The head portion 40F of the sixth embodiment is configured except that a plurality of supply valve portions 33 are driven by a common drive portion 35F and a plurality of discharge valve portions 53 are driven by a common drive portion 55F. The configuration of the head section 40C of the third embodiment (FIG. 13) is almost the same.

  The head portion 40F is configured to eject the liquid LQ from each of the plurality of nozzles 41 including at least the first nozzle 41a and the second nozzle 41b. The head portion 40F includes a plurality of liquid chambers 42 with which the nozzles 41 communicate. The plurality of liquid chambers 42 include at least a first liquid chamber 42a that communicates with the first nozzle 41a and a second liquid chamber 42b that communicates with the second nozzle 41b. Each liquid chamber 42 is provided with a liquid chamber drive unit 43. The plurality of liquid chamber driving units 43 included in the head unit 40F include a first liquid chamber driving unit 43a that changes the volume of the first liquid chamber 42a and a second liquid chamber driving unit that changes the volume of the second liquid chamber 42b. 43b.

  Each liquid chamber 42 is connected to an inflow passage 31 having a supply valve portion 33 and an outflow passage 51 having a discharge valve portion 53 one by one. The plurality of inflow paths 31 of the head portion 40F include at least a first inflow path 31a connected to the first liquid chamber 42a and a second inflow path 31b connected to the second liquid chamber 42b. include. The plurality of outflow paths 51 of the head portion 40F include at least a first outflow path 51a connected to the first liquid chamber 42a and a second outflow path 51b connected to the second liquid chamber 42b. include. The plurality of supply valve portions 33 included in the head portion 40F include at least a first supply valve portion 33a that changes the volume of the first inflow passage 31a and a second supply valve portion 33b that changes the volume of the second inflow passage 31b. And are included. The plurality of discharge valve portions 53 included in the head portion 40F include at least a first discharge valve portion 53a that changes the volume of the first outflow passage 51a and a second discharge valve portion 53b that changes the volume of the second outflow passage 51b. And are included.

  In the head part 40F, each supply valve part 33 including the first supply valve part 33a and the second supply valve part 33b is divided into the first inflow path 31a and the second inflow path by the driving force generated by the common drive part 35F. The volume of each inflow path 31 including 31b is changed. Hereinafter, the drive unit 35F is also referred to as a “supply side common drive unit 35F”. The supply-side common drive unit 35F is configured by a piezo actuator that can expand and contract in the vertical direction. The supply-side common drive unit 35F applies an external force generated by the vertical movement in the vertical direction as a drive force that changes the volume of the inflow passage 31.

  Supply side common drive part 35F gives the above-mentioned external force to each channel wall member 34 via connecting member 65Fs. The connecting member 65 </ b> Fs includes an erection portion 66 and a plurality of connecting portions 67. The erection portion 66 is configured as a columnar portion that is erected across the flow path wall members 34. Each of the plurality of connecting portions 67 is configured as a protruding portion that protrudes from the installation portion 66 toward each flow path wall member 34 below, and is in contact with and connected to each flow path wall member 34. When the supply side common drive part 35F expands and contracts, the connecting member 65Fs is displaced up and down, and each flow path wall member 34 is bent and deformed.

  In the head portion 40F, each discharge valve portion 53 including the first discharge valve portion 53a and the second discharge valve portion 53b is divided into the first outflow passage 51a and the second outflow passage by the driving force generated by the common drive portion 55F. The volume of each outflow path 51 including 51b is changed. Hereinafter, the drive unit 55F is also referred to as a “discharge-side common drive unit 55F”. The discharge-side common drive unit 55F is configured by a piezo actuator that can expand and contract in the vertical direction. The discharge-side common drive unit 55F applies an external force generated by the vertical expansion / contraction motion as a drive force that changes the volume of the outflow passage 51.

  The discharge side common drive section 55F applies the external force to each flow path wall member 54 via the connecting member 65Fe. The connecting member 65Fe has a configuration similar to that of the connecting member 65Fs provided on the inflow path 31 side, and includes an erection portion 66 and a plurality of connecting portions 67. When the discharge side common drive part 55F expands and contracts, the connecting member 65Fe is displaced up and down, and each flow path wall member 54 connected to the connecting member 65Fe via the connecting part 67 is bent and deformed.

  In the liquid ejection device according to the sixth embodiment, the control unit 80 (FIG. 7) performs the same control as described in the third embodiment on the head unit 40F. According to the liquid ejection device of the sixth embodiment, the head unit 40F can be made smaller than the configuration of the third embodiment in which the driving unit 35 is provided for each inflow path 31 and the driving unit 55 is provided for each outflow path 51. Is possible. Further, the driving of each supply valve unit 33 can be easily synchronized by the common driving units 35 and 55F, and the driving of each discharge valve unit 53 can be easily synchronized. In addition, according to the liquid ejection device of the sixth embodiment, the supply valve portion 33 and the discharge valve portion 53 can be operated separately as in the liquid ejection device of the third embodiment. In addition, according to the liquid ejection device of the sixth embodiment, the effects of the first supply valve control and the second supply valve control described in the above embodiments, the second discharge valve control, and the second discharge valve control. Various functions and effects similar to those described in the above embodiments including the effects can be obtained.

G. Seventh embodiment:
The discharge control in the seventh embodiment will be described with reference to FIGS. 26A, 26B, 26B, and 26C in order with FIG. FIG. 25 is an explanatory diagram showing a flow of discharge control in the seventh embodiment. 26A to 26C are schematic views illustrating the operation of the head unit in the ejection head. FIG. 4B is a diagram referred to in the first embodiment.

  The discharge control of the seventh embodiment is executed in the liquid discharge apparatus 100A (shown in FIGS. 1 and 2) described in the first embodiment. In the discharge control (FIG. 25) of the seventh embodiment, steps S11 and S17 are executed instead of steps S10 and S16. Finally, step S18 for executing the second supply valve control is executed. This is different from the discharge control (FIG. 3) of the first embodiment.

  Step S <b> 11 is a step for preparing to start discharging the liquid LQ from the nozzle 41. In step S11, the control unit 80 causes the supply valve unit 33 to perform a valve closing operation. The control unit 80 extends the drive unit 35 to reduce the volume of the inflow path 31 (FIG. 26A). The controller 80 reduces the volume of the inflow path 31 to a predetermined minimum volume. The minimum volume may be a volume at which the inflow path 31 described in the first embodiment is blocked.

  Note that the controller 80 determines the pressure in the liquid chamber 42 so that the internal pressure of the liquid chamber 42 after reducing the volume of the inflow path 31 in step S11 is equal to or lower than the meniscus pressure resistance of the nozzle 41 before executing step S11. It is desirable to adjust in advance. Thereby, the outflow of the liquid LQ from the nozzle 41 when the volume of the inflow path 31 is reduced is suppressed.

  In step S13, as described in the first embodiment, the control unit 80 drives the liquid chamber driving unit 43 to reduce the volume of the liquid chamber 42 and starts discharging the liquid LQ from the nozzle 41. (FIG. 4B). At this time, since the flow path resistance of the inflow path 31 is increased in step S11, the pressure generated in the liquid chamber 42 for discharging the liquid LQ is prevented from being released toward the inflow path 31. Is done.

  Step S17 is a process for separating the liquid LQ discharged from the nozzle 41 as the droplet DR. In step S <b> 17, the control unit 80 reduces the pressure of the liquid chamber 42 by contracting the liquid chamber driving unit 43 and expanding the volume of the liquid chamber 42 while the liquid LQ is being discharged from the nozzle 41. (FIG. 26B). As a result, a suction force that pulls back the liquid LQ from the nozzle 41 to the liquid chamber 42 is generated, and the liquid LQ ejected outside the nozzle 41 can be separated as a droplet DR from the liquid LQ of the nozzle 41 and caused to fly. .

  In step S <b> 17, the control unit 80 increases the volume of the liquid chamber 42 from its reference volume. Accordingly, a large negative pressure can be generated in the liquid chamber 42, and the droplet DR can be more reliably separated from the liquid LQ of the nozzle 41. Therefore, the flying state of the droplet DR is improved.

  In step S <b> 17, the supply valve portion 33 keeps the volume of the inflow path 31 smaller than the reference volume, and the state where the flow path resistance of the inflow path 31 is large is maintained. For this reason, the supply of the liquid LQ from the inflow passage 31 prevents the negative pressure generated in the liquid chamber 42 from being reduced.

In step S18, the control unit 80 performs the second supply valve control. The controller 80 increases the volume of the inflow passage 31 to the reference volume while reducing the volume of the liquid chamber 42 to the reference volume (FIG. 26C). Variation [Delta] V _R of the volume of the liquid chamber 42 at this time, the inflow channel 31 volume liquid chamber 42 flows into passage 31 flows out to the liquid LQ of the volume V _A or to the by opening operation of the supply valve 33 to increase the It is. As a result, the liquid LQ flows out to the inflow passage 31 by the valve opening operation of the supply valve section 33, and the negative pressure for sucking outside air from the nozzle 41 into the liquid chamber 42 is suppressed.

  As described above, according to the discharge control of the seventh embodiment, it is possible to suppress the outside air from entering the liquid chamber 42 through the nozzle 41 by the second supply valve control after the liquid LQ is discharged. In addition, according to the liquid ejection device 100A in the seventh embodiment, in addition to the various functions and effects described in the seventh embodiment, the various functions and effects described in the above embodiments can also be achieved. .

H. Other embodiments:
The various configurations described in the above embodiments can be modified as follows, for example. The configurations of the other embodiments described below are positioned as examples of the embodiments for carrying out the invention, like the above-described embodiments.

H1. Other Embodiment 1:
In each of the above-described embodiments (excluding the second embodiment), the supply valve portion 33 is configured to bend and deform the flow path wall member 34 configured as a part of the inner wall surface of the inflow path 31, thereby The volume is changed. On the other hand, the supply valve part 33 may change the volume of the inflow path 31 with another structure. The supply valve portion 33 may be configured by a shutter wall portion that is displaced so as to cross the inflow passage 31 and changes the flow passage cross-sectional area of the inflow passage 31, for example. Even in this configuration, the volume of the inflow path 31 changes by the amount of displacement of the shutter wall. The supply valve unit 33 may change the volume of the inflow path 31 by deforming the entire inner wall surface of the inflow path 31.

H2. Other embodiment 2:
In each of the above embodiments (excluding the first embodiment and the seventh embodiment), the discharge valve portion 53 is configured to bend and deform the flow path wall member 54 configured as a part of the inner wall surface of the outflow path 51. The volume of the outflow path 51 is changed. On the other hand, the discharge valve part 53 may change the volume of the outflow path 51 by another structure. For example, the discharge valve portion 53 may be configured by a shutter wall portion that is displaced so as to cross the outflow passage 51 and changes the flow passage cross-sectional area of the outflow passage 51. Even in this configuration, the volume of the outflow passage 51 changes by the amount of displacement of the shutter wall. Further, the discharge valve portion 53 may change the volume of the outflow passage 51 by deforming the entire inner wall surface of the outflow passage 51.

H3. Other embodiment 3:
In each of the above-described embodiments, the drive units 35, 55, and 60 are configured by piezo actuators. On the other hand, the drive units 35, 55, and 60 may be configured by an actuator other than the piezo actuator. The drive units 35, 55, and 60 may be configured by other actuators such as an air cylinder, a solenoid, and a magnetostrictive element, for example.

H4. Other embodiment 4:
In each of the embodiments described above, the liquid chamber drive unit 43 is configured by a piezo actuator. On the other hand, the liquid chamber driving unit 43 may be configured by an actuator other than the piezoelectric actuator. The liquid chamber drive unit 43 may be configured by other actuators such as an air cylinder, a solenoid, and a magnetostrictive element.

H5. Other embodiment 5:
The control of the head units 40A to 40E by the control unit 80 described in the above embodiments is merely an example, and the content of the control by the control unit 80 is limited to the control described in the above embodiments. Absent. For example, in the third embodiment, the discharge control (FIGS. 18 and 19) and the standby control (FIG. 21) described in the fourth embodiment may be executed. In the first and third embodiments described above, either one of the first supply valve control and the second supply valve control may not be executed. Further, the first supply valve control and the second supply valve control may be executed in a control other than the discharge control and the standby control. Similarly, in the second embodiment and the third embodiment described above, either one of the first discharge valve control and the second discharge valve control may not be executed. Further, the first discharge valve control and the second discharge valve control may be executed in a control other than the discharge control and the standby control. In the fourth embodiment and the fifth embodiment described above, either one of the first valve control and the second valve control may not be executed. Further, the first valve control and the second valve control may be executed in a control other than the discharge control and the standby control. The first valve control and the second valve control may be executed only in standby control. In this case, in the fourth embodiment and the fifth embodiment, the following discharge control may be executed. While reducing the volume of the inflow path 31 and the supply valve part 33 from the reference volume to the minimum volume, the liquid chamber drive part 43 abruptly reduces the volume of the liquid chamber 42 and discharges the liquid from the nozzle 41. Then, while increasing the volume of the liquid chamber 42 to return to the reference volume, the volumes of the inflow passage 31 and the supply valve unit 33 are increased to return to the reference volume.

H6. Other embodiment 6:
In the first supply valve control and the second supply valve control described in each of the above embodiments, the period during which the supply valve unit 33 is driven and the period during which the liquid chamber drive unit 43 is driven may not match. It does not have to overlap. That is, in the first supply valve control and the second supply valve control, the operation in which the liquid chamber drive unit 43 varies the volume of the liquid chamber 42 is executed in conjunction with the operation in which the supply valve unit 33 varies the volume of the inflow passage 31. It only has to be done. Here, “executed along with” means “executed in conjunction”. In the first supply valve control and the second supply valve control, the start and end of the drive period of the supply valve section 33 and the start and end of the drive period of the liquid chamber drive section 43 are the relationship between the inflow path 31 and the liquid chamber 42. It is only necessary that the liquid LQ is appropriately adjusted and set in consideration of the time for the liquid LQ to move between them. The same applies to the start and end of the drive period of the discharge valve unit 53 and the start and end of the drive period of the liquid chamber drive unit 43 in the first discharge valve control and the second discharge valve control. In addition, the start and end of the drive period of the supply valve unit 33, the start and end of the drive period of the discharge valve unit 53, and the start and end of the drive period of the liquid chamber drive unit 43 in the first valve control and the second valve control. The same applies to. According to the interpretation of the term “accompanied”, the first supply valve control for increasing the volume of the liquid chamber 42 as the volume of the inflow path 31 is decreased is slightly reduced. After the reduction, a control mode in which the operation of slightly increasing the volume of the liquid chamber 42 is repeated alternately is included. Further, in the second supply valve control for decreasing the volume of the liquid chamber 42 as the volume of the inflow path 31 is increased, the volume of the liquid chamber 42 is increased after the volume of the inflow path 31 is slightly increased. A control mode in which the slightly decreasing operation is alternately repeated is included. Similarly, in the first discharge valve control in which the liquid chamber 42 is increased as the volume of the outflow path 51 is decreased, the volume of the liquid chamber 42 is slightly decreased after the volume of the outflow path 51 is slightly decreased. A control mode in which the increasing operation is alternately repeated is included. In addition, in the second discharge valve control for decreasing the volume of the liquid chamber 42 as the volume of the outflow path 51 is increased, the volume of the liquid chamber 42 is increased after the volume of the outflow path 51 is slightly increased. A control mode in which the slightly decreasing operation is alternately repeated is included.

H7. Other embodiment 7:
In the liquid ejection device 100A of the first embodiment, a configuration in which the outflow passage 51 connected to the liquid chamber 42 as described in the second embodiment and later is provided may be applied.

H8. Other embodiment 8:
In the sixth embodiment, only the discharge valve portion 53 is driven by the discharge-side common drive portion 55F, and the supply valve portion 33 is provided for each supply valve portion 33 as in the head portion 40C of the third embodiment. A configuration of driving by the driving unit 35 may be applied. Conversely, only the supply valve unit 33 is driven by the supply-side common drive unit 35F, and the discharge valve unit 53 is driven by the drive unit 55 provided for each discharge valve unit 53 in the same manner as the head unit 40C of the third embodiment. A driving configuration may be applied.

H9. Other embodiment 9:
In each of the above embodiments, the plurality of inflow passages 31 and the plurality of outflow passages 51 may include those in which the supply valve portion 33 and the discharge valve portion 53 are not provided. In the case where the head unit 40D of the fourth embodiment is configured to discharge the liquid LQ from the plurality of nozzles 41, the supply valve unit 33 and the discharge valve unit 53 are driven by separate driving units. It may be included. Also in the head unit 40E of the fifth embodiment, the plurality of sets of supply valve unit 33 and discharge valve unit 53 may include those driven by a drive unit different from the common drive unit 60. Also in the head part 40F of the sixth embodiment, the plurality of supply valve parts 33 may include a supply valve part 33 driven by a drive part different from the supply side common drive part 35F, or a plurality of supply valve parts 33 may be included. The discharge valve portion 53 may include a discharge valve portion 53 that is driven by a drive unit different from the discharge side common drive unit 55F.

H10. Other embodiment 10:
The present invention is not limited to a liquid ejecting apparatus that ejects ink, but can be applied to any liquid ejecting apparatus that ejects liquid other than ink. For example, the present invention is applicable to the following various liquid ejection devices.
(1) An image recording apparatus such as a facsimile apparatus.
(2) A color material discharge device used for manufacturing a color filter for an image display device such as a liquid crystal display.
(3) An electrode material discharge device used for electrode formation such as an organic EL (Electro Luminescence) display and a surface emission display (Field Emission Display, FED).
(4) A liquid ejection device that ejects a liquid containing a bio-organic material used for biochip manufacture.
(5) Sample discharge device as a precision pipette.
(6) A lubricating oil discharge device.
(7) Resin liquid discharge device.
(8) A liquid ejection device that ejects lubricating oil pinpoint to precision machines such as watches and cameras.
(9) A liquid ejection apparatus that ejects a transparent resin liquid such as an ultraviolet curable resin liquid onto a substrate in order to form a micro hemispherical lens (optical lens) used for an optical communication element or the like.
(10) A liquid discharge apparatus that discharges an acidic or alkaline etchant to etch a substrate or the like.
(11) A liquid discharge apparatus including a liquid discharge head that discharges another arbitrary minute amount of liquid droplets.

H11. Other embodiment 11:
In the above embodiment, some or all of the functions and processes realized by software may be realized by hardware. In addition, some or all of the functions and processes realized by hardware may be realized by software. As the hardware, for example, various circuits such as an integrated circuit, a discrete circuit, or a circuit module combining these circuits can be used.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. In addition, the technical features are not limited to those described in the specification as being essential, and if the technical features are not described as essential in the specification, they may be deleted as appropriate. Is possible.

  The “inflow path 31” and the “outflow path 51” in each of the above embodiments correspond to a subordinate concept of “flow path”. The “supply valve portion 33” and the “discharge valve portion 53” correspond to subordinate concepts of the “valve portion”. The “first supply valve control”, “first discharge valve control”, and “first valve control” respectively change the volume of the liquid chamber while the volume of the flow path fluctuates. "First control" in which the volume of the liquid chamber is increased by the liquid chamber drive unit as the volume of the flow path in the valve unit is decreased so as to be equal to or greater than the volume of the liquid flowing into the liquid chamber from It corresponds to the subordinate concept of. “Second supply valve control”, “second discharge valve control”, and “second valve control” are respectively performed when the change amount of the volume of the liquid chamber is changed while the volume of the flow path is fluctuating. The volume of the liquid chamber is decreased in the liquid chamber drive unit as the volume of the flow path is increased in the valve unit so that the volume of the liquid flows out from the liquid chamber to the flow path. This corresponds to a subordinate concept of “second control”.

  In this specification, the “liquid” may be any material that can be consumed by the liquid ejection device. For example, the “liquid” may be a material in a state in which the substance is in a liquid phase, such as a material in a liquid state having high or low viscosity, and sol, gel water, other inorganic solvents, organic solvents, solutions, Liquid materials such as liquid resins and liquid metals (metal melts) are also included in the “liquid”. Further, “liquid” includes not only a liquid as one state of a substance but also a liquid obtained by dissolving, dispersing or mixing particles of a functional material made of a solid such as a pigment or metal particles in a solvent. Typical examples of the liquid include ink and liquid crystal. Here, the ink includes various liquid compositions such as general water-based ink and oil-based ink, gel ink, and hot-melt ink. The “droplet” refers to the state of the liquid ejected from the liquid ejecting apparatus, and includes those that have tails in the form of particles, tears, and threads.

DESCRIPTION OF SYMBOLS 10 ... Tank, 15 ... Pressure adjustment part, 20 ... Pressure pump, 30 ... Supply path, 31 ... Inflow path, 31a ... 1st inflow path, 31b ... 2nd inflow path, 33 ... Supply valve part, 33a ... 1st Supply valve part, 33b ... 2nd supply valve part, 34 ... Channel wall member, 35 ... Drive part, 35F ... Drive part (supply side common drive part), 40A ... Head part, 40B ... Head part, 40C ... Head part , 40D ... head portion, 40E ... head portion, 40F ... head portion, 41 ... nozzle, 41a ... first nozzle, 41b ... second nozzle, 42 ... liquid chamber, 42a ... first liquid chamber, 42b ... second liquid chamber 42e ... bottom surface, 43 ... liquid chamber drive unit, 45 ... top surface, 50 ... discharge channel, 51 ... outflow channel, 51a ... first outflow channel, 51b ... second outflow channel, 53 ... discharge valve unit, 53a ... first 1 discharge valve part, 53b ... 2nd discharge valve part, 54 ... flow-path wall member, 55 ... drive part, 55F Drive part (discharge side common drive part), 60 ... drive part, 65 ... connecting member, 65E ... connecting member, 65Fe ... connecting member, 65Fs ... connecting member, 66 ... installation part, 67 ... connecting part, 68 ... connecting plate, DESCRIPTION OF SYMBOLS 70 ... Liquid storage part, 75 ... Negative pressure generation source, 80 ... Control part, 90 ... Circulation path, 100A ... Liquid ejection apparatus, 100B ... Liquid ejection apparatus, DR ... Droplet, LQ ... Liquid, _VA ... Supply side movement Volume, V _B ... discharge side moving volume, V _C ... moving volume, ΔV _R ... change amount

Claims (9)

A liquid ejection device comprising:
A liquid chamber communicating with the nozzle and containing a liquid;
A liquid chamber driving section for changing the volume of the liquid chamber and discharging the liquid from the nozzle;
A flow path connected to the liquid chamber and through which the liquid flows;
The flow of the liquid between the liquid chamber and the flow path is controlled by changing the flow path resistance of the flow path by changing the volume of the flow path by displacing the inner wall surface of the flow path. A valve part to
A control unit for controlling the liquid chamber driving unit and the valve unit;
With
The controller is
(I) As the volume of the flow path is reduced in the valve section, the amount of change in the volume of the liquid chamber is reduced due to the decrease in the volume of the flow path. A first control for increasing the volume of the liquid chamber in the liquid chamber drive unit so as to be equal to or greater than the volume;
(Ii) As the volume of the flow path is increased in the valve portion, the amount of change in the volume of the liquid chamber is increased by the increase in volume of the flow path. A second control for reducing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or larger than the volume;
A liquid ejection apparatus that executes at least one of the above. The liquid ejection device according to claim 1,
The flow path includes an inflow path through which the liquid supplied to the liquid chamber flows,
The valve portion includes a supply valve portion that is provided in the inflow passage and changes a volume of the inflow passage,
In the first control, as the volume of the inflow passage is decreased in the supply valve portion, the change amount of the volume of the liquid chamber flows into the liquid chamber from the inflow passage due to the decrease in the volume of the inflow passage. Including a first supply valve control for increasing the volume of the liquid chamber in the liquid chamber drive unit so as to be equal to or greater than the volume of the liquid.
In the second control, as the volume of the inflow passage is increased in the supply valve portion, the amount of change in the volume of the liquid chamber flows out from the liquid chamber to the inflow passage due to the increase in the volume of the inflow passage. A liquid ejecting apparatus comprising: a second supply valve control for reducing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or greater than the volume of the liquid. The liquid ejection device according to claim 2,
The liquid chamber includes a first liquid chamber communicating with the first nozzle, and a second liquid chamber communicating with the second nozzle,
The liquid chamber drive unit includes a first liquid chamber drive unit that changes the volume of the first liquid chamber, and a second liquid chamber drive unit that changes the volume of the second liquid chamber,
The inflow path includes a first inflow path connected to the first liquid chamber, and a second inflow path connected to the second liquid chamber,
The supply valve portion includes a first supply valve portion that changes the volume of the first inflow passage, and a second supply valve portion that changes the volume of the second inflow passage,
In the first control and the second control, the control unit causes the second supply valve unit to change the volume of the second inflow path while changing the volume of the first inflow path in the first supply valve unit. Along with the change, the second liquid chamber drive unit changes the volume of the second liquid chamber while the first liquid chamber drive unit changes the volume of the first liquid chamber,
The first supply valve portion and the second supply valve portion are liquid ejection devices that change the volumes of the first inflow passage and the second inflow passage by a driving force generated by a common drive portion. The liquid ejection device according to claim 1,
The flow path includes an inflow path through which the liquid supplied to the liquid chamber flows, and an outflow path through which the liquid discharged from the liquid chamber flows.
The valve portion includes a discharge valve portion that displaces an inner wall surface of the outflow passage to change a volume of the outflow passage,
In the first control, as the volume of the outflow path is decreased in the discharge valve portion, the change amount of the volume of the liquid chamber flows into the liquid chamber from the outflow path due to the decrease in the volume of the outflow path. Including a first discharge valve control for increasing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or greater than the volume of the liquid.
In the second control, as the volume of the outflow path is increased in the discharge valve portion, the change amount of the volume of the liquid chamber flows into the liquid chamber from the outflow path due to the increase in the volume of the outflow path. A liquid discharge apparatus comprising: a second discharge valve control for reducing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or larger than the volume of the liquid. The liquid ejection device according to claim 4,
The liquid chamber includes a first liquid chamber communicating with the first nozzle, and a second liquid chamber communicating with the second nozzle,
The liquid chamber drive unit includes a first liquid chamber drive unit that changes the volume of the first liquid chamber, and a second liquid chamber drive unit that changes the volume of the second liquid chamber,
The inflow path includes a first inflow path connected to the first liquid chamber, and a second inflow path connected to the second liquid chamber,
The outflow path includes a first outflow path connected to the first liquid chamber, and a second outflow path connected to the second liquid chamber,
The discharge valve portion includes a first discharge valve portion that changes the volume of the first outflow passage, and a second discharge valve portion that changes the volume of the second outflow passage,
In the first control and the second control, the control unit causes the second discharge valve unit to change the volume of the second outflow path while changing the volume of the first outflow path in the first discharge valve unit. Along with the change, the second liquid chamber drive unit changes the volume of the second liquid chamber while the first liquid chamber drive unit changes the volume of the first liquid chamber,
The first discharge valve section and the second discharge valve section are liquid ejection devices that change the volumes of the first outflow path and the second outflow path by a driving force generated by a common driving section. The liquid ejection device according to claim 1,
The flow path includes an inflow path through which the liquid supplied to the liquid chamber flows, and an outflow path through which the liquid discharged from the liquid chamber flows.
The valve section includes a supply valve section that changes the volume of the inflow path by displacing the inner wall surface of the inflow path, and a discharge valve section that changes the volume of the outflow path by displacing the inner wall surface of the outflow path. Including,
In the first control, as the volume of the outflow passage is reduced in the discharge valve portion while the volume of the outflow passage is reduced in the discharge valve portion, the change amount of the volume of the liquid chamber is reduced. The volume of the liquid chamber is increased in the liquid chamber drive unit so that the volume of the liquid and the flow out of the liquid flow into the liquid chamber from the outflow path and the outflow path by decreasing the volume of the flow path and the volume of the outflow path. Including a first valve control,
As the second control increases the volume of the inflow passage to the supply valve portion and increases the volume of the outflow passage to the discharge valve portion, the amount of change in the volume of the liquid chamber is changed to the inflow amount. The volume of the liquid chamber is reduced in the liquid chamber driving unit so that the volume of the liquid and the outflow path is increased to exceed the volume of the liquid flowing into the liquid chamber from the inflow path and the outflow path. A liquid discharge device including a second valve control. The liquid ejection device according to claim 6,
The supply valve unit and the discharge valve unit are liquid ejection devices that change the volume of the outflow path and the volume of the inflow path by a driving force generated by a common driving unit. The liquid ejection apparatus according to any one of claims 4 to 7,
A liquid discharge apparatus comprising a circulation path for circulating the liquid discharged to the outflow path to the inflow path. A liquid chamber that communicates with the nozzle and contains a liquid; a liquid chamber driving unit that changes the volume of the liquid chamber to discharge the liquid from the nozzle; and a flow path that is connected to the liquid chamber and through which the liquid flows. The flow of the liquid between the liquid chamber and the flow path is changed by changing the flow path resistance of the flow path by changing the volume of the flow path by displacing the inner wall surface of the flow path. And a control method of a liquid ejection device comprising:
(I) As the volume of the flow path is reduced in the valve section, the amount of change in the volume of the liquid chamber is reduced due to the decrease in the volume of the flow path. A first control for increasing the volume of the liquid chamber in the liquid chamber drive unit so as to be equal to or greater than the volume;
(Ii) As the volume of the flow path is increased in the valve portion, the amount of change in the volume of the liquid chamber is increased by the increase in volume of the flow path. A second control for reducing the volume of the liquid chamber in the liquid chamber driving unit so as to be equal to or larger than the volume;
A control method comprising a step of executing at least one of the methods.

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