LIQUID EJECTION HEAD AND LIQUID EJECTION APPARATUS

Abstract

To provide a liquid ejection head in which load applied to an actuator is reduced and which therefore can secure a sufficient life.SOLUTION: A liquid ejection head comprises: a liquid ejection port for ejecting a liquid; a flow channel communicating with the liquid ejection port; a valve element that opens / closes the liquid ejection port; and an actuator that drives the valve element. The liquid ejection head ejects a liquid supplied to the flow channel, from the liquid ejection port during the period of time that the valve element opens the liquid ejection port. A plurality of actuators is provided for one of the valve elements.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus. [Background technology]

[0002] Patent Document 1 discloses a droplet ejection head in which ejection liquid is pressurized and supplied to a cavity 23 communicating with a nozzle 22, the nozzle 22 can be blocked by a pin 24, the pin 24 can be moved toward and away from the nozzle 22 by an actuator 25, and the actuator 25 is controlled by a control device 12, so that the ejection liquid supplied under pressure is ejected as droplets from the nozzle 22 only while the pin 24 is away from the nozzle 22. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a liquid ejection head capable of reducing the load on an actuator and ensuring a sufficient lifespan. [Means for solving the problem]

[0004] The present invention relates to a liquid ejection head that includes a liquid ejection port for ejecting liquid, a flow path that communicates with the liquid ejection port, a valve body that opens and closes the liquid ejection port, and an actuator that drives the valve body, and that ejects liquid that has been supplied to the flow path from the liquid ejection port while the valve body is open. The actuators may not be driven simultaneously. It is characterized by: Effect of the Invention

[0005] According to the present invention, it is possible to provide a liquid ejection head that can reduce the load on the actuator and ensure a sufficient lifespan. [Brief description of the drawings]

[0006] [Figure 1]1 is an overall perspective view showing an example of a liquid ejection head according to the present invention. [Diagram 2] FIG. 2 is an overall cross-sectional view of a liquid ejection head. [Diagram 3] FIG. 4 is an explanatory diagram of a single liquid ejection module. [Figure 4] 4 is a control timing chart for an actuator. [Diagram 5] 1 is an overall perspective view showing an example of a liquid ejection device according to the present invention. [Figure 6] FIG. [Figure 7] Control block diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

[0008] FIG. 1 is an overall perspective view showing an example of a liquid ejection head according to the present invention.

[0009] The liquid ejection head 300 mainly includes a housing 310, a connector 350, a supply port 311, and a recovery port 313. The housing 310 is made of a metal material or a resin material. An upper portion of the housing 310 includes a connector 350 for communicating electrical signals.

[0010] Further, on the left and right sides of the housing 310, there are provided a supply port 311 for supplying liquid into the head, and a recovery port 313 for discharging liquid from the head.

[0011] FIG. 2 is an overall cross-sectional view of the liquid ejection head according to the present invention (a cross-sectional view taken along line AA in FIG. 1).

[0012] The housing 310 has a connector 350 for communicating electrical signals at its upper portion, and holds a nozzle plate 301 equipped with nozzles 302 for discharging liquid at its lower portion. The housing 310 also has a flow path 312 for sending liquid from the supply port 311 side through the nozzle plate 301 to the recovery port 313 side.

[0013] Between the supply port 311 and the recovery port 313, a liquid ejection module 330 (details will be described later) is disposed for ejecting ink in the flow path 312 from the nozzles 302. The number of liquid ejection modules 330 corresponds to the number of nozzles 302, and in this example, a configuration is shown that includes eight liquid ejection modules 330 corresponding to the eight nozzles 302 arranged in a row.

[0014] It should be noted that the number and arrangement of the nozzles 302 and liquid ejection modules 330 are not limited to those described above. For example, the number of nozzles 302 and liquid ejection modules 330 may be one instead of multiple. Furthermore, the nozzles 302 and liquid ejection modules 330 may be arranged in multiple rows instead of one row.

[0015] With the above configuration, the supply port 311 takes in pressurized liquid from the outside, sends the liquid in the direction of the arrow a1, and supplies the liquid to the flow path 312. The flow path 312 sends the liquid from the supply port 311 in the direction of the arrow a2. Then, the recovery port 313 discharges the liquid that has not been ejected from the nozzles 302 arranged along the flow path 312 in the direction of the arrow a3.

[0016] The liquid ejection module 330 includes a needle valve 331 that opens and closes the nozzle 302, and a piezoelectric element 332 that drives the needle valve 331. The housing 310 includes a regulating member 314 at a position facing the upper end of the piezoelectric element 332. The regulating member 314 abuts against the upper end of the piezoelectric element 332, and serves as a fixing point for the piezoelectric element 332. Here, the needle valve 331 is an example of a valve body, and the piezoelectric element 332 is an example of an actuator.

[0017] In the above configuration, when the piezoelectric element 332 is operated and the needle valve 331 is displaced upward in the figure, the nozzle 302 that was closed by the needle valve 331 opens, and liquid is discharged from the nozzle 302. When the piezoelectric element 332 is operated and the needle valve 331 is displaced downward, the tip of the needle valve 331 comes into contact with the nozzle 302, closing the nozzle 302, and liquid is no longer discharged from the nozzle 302.

[0018] During the period when liquid is being discharged from the nozzle 302, in order to prevent a decrease in the efficiency of discharge from the nozzle 302, the discharge of liquid from the recovery port 313 may be temporarily suspended.

[0019] FIG. 3 is an explanatory diagram of a single liquid ejection module that constitutes the liquid ejection head.

[0020] The liquid ejection module 330 includes a needle valve 331 that opens and closes the nozzle 302, and a piezoelectric element 332 that drives the needle valve 331. The nozzle plate 301 is joined to a housing 310. In addition, a flow path 312 is a flow path common to a plurality of liquid ejection modules 330 provided in the housing 310.

[0021] The tip of needle valve 331 is provided with elastic member 331a, which reliably closes nozzle 302 when the tip of needle valve 331 is pressed against nozzle plate 301. In addition, a bearing 321 is provided between needle valve 331 and housing 310, and a seal member 315 such as an O-ring is provided between bearing 321 and needle valve 331.

[0022] The piezoelectric element 332 is accommodated in the space 322 of the housing 310 via a holding member 333. The holding member 333 is made up of seven members 333a to 333g. The member 333a located at the bottom of the holding member 333 holds the upper end of the needle valve 331. The space formed by the members 333a, 333b, 333c, and 333d holds the first piezoelectric element 3321. The space formed by the members 333d, 333e, 333f, and 333g holds the second piezoelectric element 3322.

[0023] A part of member 333g located at the upper part of holding member 333 abuts against restricting member 314, forming a fixed point to prevent holding member 333 from moving upward. Moreover, seven members 333a to 333g constituting holding member 333 are each connected via elastic body 333h such as a leaf spring.

[0024] With the above configuration, the needle valve 331, the first piezoelectric element 3321, and the second piezoelectric element 3322 are arranged coaxially, i.e., in series in the liquid discharge direction, via the holding member 333. Note that the holding member 333 is made of stainless steel or other material that is less susceptible to thermal expansion (such as Invar).

[0025] The first piezoelectric element 3321 and the second piezoelectric element 3322 are arranged so that their displacement directions are the same, and when a voltage is applied to the two piezoelectric elements by a voltage application means (not shown), the two piezoelectric elements drive the needle valve 331 in a direction to open the nozzle 302. Therefore, when no voltage is applied to the piezoelectric element 332, the needle valve 331 closes the nozzle 302, so that no liquid is discharged from the nozzle 302 even if liquid is supplied under pressure to the flow path 312.

[0026] When a voltage is applied to the piezoelectric element 332, the piezoelectric element 332 contracts and pulls the needle valve 331 via the holding member 333, causing the needle valve 331 to move away from the nozzle 302 and open the nozzle 302. As a result, the liquid supplied under pressure to the flow path 312 is discharged from the nozzle 302.

[0027] In the above description, the two piezoelectric elements 3321, 3322 are arranged in series in the liquid ejection direction, but the arrangement of the piezoelectric elements is not limited to this. For example, the two piezoelectric elements 3321, 3322 may be arranged in parallel. Furthermore, the number of piezoelectric elements is not limited to two, and may be three or more.

[0028] As described above, this embodiment is a liquid ejection head 300 comprising a nozzle 302 that ejects liquid, a flow path 312 communicating with the nozzle 302, a needle valve 331 that opens and closes the nozzle 302, and a piezoelectric element 332 that drives the needle valve 331, and ejects liquid supplied to the flow path 312 from the nozzle 302 while the needle valve 331 opens the nozzle 302, and multiple piezoelectric elements 3321, 3322 are provided for each needle valve 331.

[0029] As described above, the piezoelectric elements 3321 and 3322 have the same displacement direction.

[0030] Furthermore, as described above, a plurality of piezoelectric elements 3321, 3322 are arranged in series in the liquid ejection direction.

[0031] This makes it possible to provide a liquid ejection head that reduces the load on the piezoelectric element and ensures a sufficient lifespan.

[0032] FIG. 4 is a control timing chart of the actuator.

[0033] 4(a) shows a case where the first piezoelectric element 3321 and the second piezoelectric element 3322 are alternately driven. In this case, the first piezoelectric element 3321 and the second piezoelectric element 3322 are alternately driven in response to a drive waveform from the head drive control unit 902 (details of which will be described in FIG. 7). For example, the two piezoelectric elements are alternately driven such that the first piezoelectric element 3321 is driven by a drive pulse for the first drop, the second piezoelectric element 3322 is driven by a drive pulse for the second drop, and the first piezoelectric element 3321 is driven by a drive pulse for the third drop.

[0034] The cycle of alternating between the two piezoelectric elements is not limited to every liquid ejection. For example, the first piezoelectric element 3321 may be driven multiple times, and then the second piezoelectric element 3322 may be driven the same number of times, so that the two piezoelectric elements are repeatedly switched between every predetermined number of drives.

[0035] As described above, by making it so that there are times when the first piezoelectric element 3321 and the second piezoelectric element 3322 are not driven simultaneously, the drive frequency of a single piezoelectric element can be halved, and the load on the piezoelectric element can be reduced.

[0036] Fig. 4(b) is an embodiment different from Fig. 4(a), and shows a case where the needle valve 331 is moved by sharing between the first piezoelectric element 3321 and the second piezoelectric element 3322. In other words, when the voltage applied to the piezoelectric element required to open and close the nozzle 302 is Vx, a voltage of Vx / 2 is applied to each of the piezoelectric elements 3321 and 3322. Then, in response to the drive waveform from the head drive control unit 902, a voltage of Vx / 2 is applied to the first piezoelectric element 3321 and the second piezoelectric element 3322 in the same cycle.

[0037] FIG. 4(c) shows a case where the needle valve 331 is moved by being shared between the first piezoelectric element 3321 and the second piezoelectric element 3322, similar to FIG. 4(b). While FIG. 4(b) is viewed from the viewpoint of applied voltage, FIG. 4(c) is different in that it is viewed from the viewpoint of displacement. That is, when the displacement amount of the needle valve 331 required to open and close the nozzle 302 is x, each of the piezoelectric elements 3321 and 3322 generates a displacement amount of x / 2. Then, in response to the drive waveform from the head drive control unit 902, the first piezoelectric element 3321 and the second piezoelectric element 3322 generate a displacement amount of x / 2 in the same cycle.

[0038] The applied voltage Vx and the displacement amount x are not limited to being constant values, but may be variable according to input data.

[0039] As described above, in this embodiment, the plurality of piezoelectric elements 3321, 3322 are sometimes not driven simultaneously.

[0040] As described above, the piezoelectric elements 3321 and 3322 are alternately driven. As described above, the piezoelectric elements 3321 and 3322 are driven by repeatedly switching between the piezoelectric elements 3321 and 3322 every predetermined number of drives. Do.

[0041] Furthermore, as described above, if the applied voltage to the piezoelectric element required to open and close the nozzle 302 is Vx, then the multiple piezoelectric elements 3321, 3322 are each driven with a voltage of Vx / 2 (the denominator is the number of piezoelectric elements) and with the same period.

[0042] Furthermore, as described above, if the amount of displacement of needle valve 331 required to open and close nozzle 302 is x, then multiple piezoelectric elements 3321, 3322 are each driven with a displacement of x / 2 (the denominator is the number of piezoelectric elements) at the same cycle.

[0043] This makes it possible to halve the drive frequency of the piezoelectric element itself, thereby reducing the load on the piezoelectric element.

[0044] As described above, the applied voltage Vx is variable according to the input data, and the displacement amount x is variable according to the input data.

[0045] This makes it possible to eject large droplets by increasing the applied voltage Vx and the displacement x, and to eject small droplets by decreasing the applied voltage Vx and the displacement x, making it possible to flexibly respond to the size of the droplets to be ejected.

[0046] FIG. 5 is an overall perspective view of a printing apparatus shown as an example of a liquid ejection apparatus according to the present invention.

[0047] The printing device 1000 is installed facing a drawing target 100, which is an example of an object. The printing device 1000 includes an X-axis rail 101, a Y-axis rail 102 that intersects with the X-axis rail 101, and a Z-axis rail 103 that intersects with the X-axis rail 101 and the Y-axis rail 102.

[0048] The Y-axis rail 102 holds the X-axis rail 101 so that the X-axis rail 101 can move in the Y direction (positive and negative sides). The X-axis rail 101 also holds the Z-axis rail 103 so that the Z-axis rail 103 can move in the X direction (positive and negative sides). The Z-axis rail 103 then holds the carriage 1 so that the carriage 1 can move in the Z direction (positive and negative sides). Here, the carriage 1 is an example of a liquid ejection unit.

[0049] The printing device 1000 includes a first Z-direction drive unit 92 that moves the carriage 1 in the Z direction along the Z-axis rail 103, and an X-direction drive unit 72 that moves the Z-axis rail 103 in the X direction along the X-axis rail 101. The printing device 1000 also includes a Y-direction drive unit 82 that moves the X-axis rail 101 in the Y direction along the Y-axis rail 102. The printing device 1000 also includes a second Z-direction drive unit 93 that moves the head holder 70 in the Z direction relative to the carriage 1. Here, the head holder 70 is an example of a holder.

[0050] The printing device 1000 configured as described above ejects ink, which is an example of liquid, from a liquid ejection head provided on the head holder 70 while moving the carriage 1 in the X, Y, and Z directions, to perform drawing on the drawing target 100. Note that the movement of the carriage 1 and head holder 70 in the Z direction does not necessarily mean that it is parallel to the Z direction, and may be an oblique movement as long as it includes at least a component in the Z direction.

[0051] In FIG. 5, the surface shape of the drawing object 100 is flat, but the surface shape of the drawing object 100 may be a nearly vertical surface, such as the body of a car or truck or the body of an aircraft, a surface with a large radius of curvature, or a surface with some unevenness.

[0052] FIG. 6 is an overall perspective view of the carriage of the printing device shown in FIG. 5, in which the carriage 1 is seen from the side of the object 100 to be drawn.

[0053] The carriage 1 includes a head holder 70. The carriage 1 is also movable in the Z direction (positive and negative sides) along a Z-axis rail 103 by power from a first Z-direction drive unit 92 shown in FIG.

[0054] The head holder 70 is movable in the Z direction (positive and negative sides) relative to the carriage 1 by power from a second Z direction drive unit 93 shown in Fig. 5. The head holder 70 also includes a head fixing plate 70a for mounting the liquid ejection head 300.

[0055] In this embodiment, a configuration is shown in which six liquid ejection heads 300 described with reference to FIGS. 1 to 3 are attached to the head fixing plate 70a, and the six liquid ejection heads 300a to 300f are arranged in a stacked manner.

[0056] Each of the liquid ejection heads 300a to 300f includes a plurality of nozzles 302. The type and number of ink colors used by the heads 300a to 300f may be different for each head, or may all be the same color. For example, if the liquid ejection device exemplified as the printing device 1000 is a coating device that uses a single color, the inks used by the heads 300a to 300f may be the same color. Furthermore, the number of heads constituting the head 300 is not limited to six. It may be more than six, or may be less than six.

[0057] The liquid ejection heads 300 are fixed to the head fixing plate 70a with the nozzle rows of each head intersecting the horizontal plane (XZ plane) and the arrangement direction of the multiple nozzles 302 tilted with respect to the X axis as shown in the figure. In this state, the nozzles 302 eject ink in a direction intersecting the direction of gravity (positive side of the Z direction). Here, the nozzles 302 are an example of a liquid ejection port.

[0058] FIG. 7 is a block diagram of the ink ejection control and its surroundings in a printing apparatus shown as an example of a liquid ejection apparatus according to the present invention.

[0059] The printing apparatus 1000 includes a controller 901, a head drive control unit 902, etc. A computer 903 is also connected to the controller 901. The computer 903 includes a RIP (Routing Information Protocol) unit 9031, a rendering unit 9032, etc.

[0060] The RIP unit 9031 has a function of performing image processing according to a color profile and user settings. The rendering unit 9032 has a function of decomposing image data to be drawn on the drawing target 100 (see FIG. 5) into image data for each scan (for example, each unit of drawing by one movement of the carriage 1 in the positive (or negative) X-axis direction). Here, the image data is an example of input data.

[0061] An input device 9033 is also connected to the computer 903. The input device 9033 is made up of a keyboard, a mouse, a touch panel, etc., and receives input from a user, such as image data to be drawn on the drawing target 100, setting of coordinate data, selection of a drawing mode, etc.

[0062] The controller 901 includes a system control unit 9011, an image data storage unit 9012, a memory control unit 9013, an ejection period signal generating unit 9014, and a carriage control unit 9015. The system control unit 9011 receives image data and commands from the computer 903, and controls the overall operation of the printing apparatus 1000.

[0063] The image data storage unit 9012 includes memories such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a HDD (Hard Disk Drive), and stores image data and the like received from the computer 903. The memory control unit 9013 writes image data and the like to the image data storage unit 9012 and reads image data and the like from the image data storage unit 9012 based on instructions from the system control unit 9011.

[0064] The ejection period signal generating unit 9014 generates an ink ejection period signal based on the output signal of the encoder sensor 109 and information indicating the resolution of the image data received from the computer 903 .

[0065] Here, the encoder sensor 109 generates the above-mentioned output signal by optically detecting, for example, a slit of a linear encoder (not shown) installed along the X-axis rail 101 of the printing device 1000. Note that the encoder sensor 109 is not limited to a linear encoder type as long as it is configured to detect the X-direction position of the carriage 1. Instead of the linear encoder type, for example, it may be replaced with a type that counts the rotations of the drive motor of the X-direction drive unit 72.

[0066] The carriage control unit 9015 calculates position information of the carriage 1 based on the output signal of the encoder sensor 109, and controls the speed of the X-direction driving unit 72. In this example, the system control unit 9011 calculates the amount of change in the moving speed of the carriage 1. Then, the system control unit 9011 controls the speed of the carriage 1 based on this amount of change.

[0067] As described above, the controller 901 includes a system control unit 9011, an image data storage unit 9012, a memory control unit 9013, an ejection period signal generating unit 9014, and a carriage control unit 9015. The controller 901 has an arithmetic processing unit and a storage device, and realizes each of these functional units by the arithmetic processing unit executing a program pre-recorded in the storage device.

[0068] Next, a description will be given of the head drive control unit 902. The head drive control unit 902, which controls the driving of the liquid ejection head 300, includes a drive waveform data storage unit 9021, a drive waveform generation unit 9022, a D / A converter 9023, a voltage amplifier 9024, and a current amplifier 9025. The drive waveform data storage unit 9021 stores a drive waveform for driving the liquid ejection head 300.

[0069] The drive waveform generation unit 9022 outputs the drive waveform data read out from the drive waveform data storage unit 9021 to a D / A converter 9023 in response to an ejection period signal from the ejection period signal generation unit 9014. The D / A converter 9023 converts the drive waveform data received from the drive waveform generation unit 9022 into analog data, and outputs the analog data to a voltage amplification unit 9024. The voltage amplification unit 9024 amplifies the voltage of the analog data received from the D / A converter 9023. In addition, the current amplification unit 9025 amplifies the current of the analog data received from the voltage amplification unit 9024.

[0070] As described above, the head drive control unit 902 includes a drive waveform data storage unit 9021, a drive waveform generation unit 9022, a D / A converter 9023, a voltage amplifier 9024, and a current amplifier 9025. The drive waveform generated by the head drive control unit 902 realizes drive control for each nozzle of the liquid ejection head 300.

[0071] For example, the RIP unit 9031 and the rendering unit 9032 may be provided in the system control unit 9011 of the controller 901 instead of in the computer 903.

[0072] In the present invention, the liquid may be a solution, suspension, emulsion, etc. containing a solvent such as water or an organic solvent, a colorant such as a dye or a pigment, a functionality-imparting material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural dye, or the like.

[0073] These can be used, for example, in ink-jet inks, coating materials, surface treatment liquids, components of electronic elements and light-emitting elements, liquids for forming electronic circuit resist patterns, and material liquids for three-dimensional modeling.

[0074] The liquid ejection device according to the present invention is not limited to the above-mentioned printing device, and may be, for example, a robot arm of a multi-joint robot that has multiple joints and can move freely like a human arm, with the liquid ejection head of the present invention attached to the tip of the robot arm.

[0075] The above description is merely an example, and the present invention provides unique effects for each of the following aspects.

[0076] [First aspect] The first aspect is a liquid ejection head (e.g., liquid ejection head 300) comprising a liquid ejection outlet (e.g., nozzle 302) for ejecting liquid, a flow path (e.g., flow path 312) communicating with the liquid ejection outlet, a valve body (e.g., needle valve 331) for opening and closing the liquid ejection outlet, and an actuator (e.g., piezoelectric element 332) for driving the valve body, and ejecting liquid supplied to the flow path from the liquid ejection outlet while the valve body opens the liquid ejection outlet, characterized in that multiple actuators (e.g., first piezoelectric element 3321 and second piezoelectric element 3322) are provided for one of the valve bodies.

[0077] [Second aspect] The second aspect is the first aspect, characterized in that the plurality of actuators (for example, the first piezoelectric element 3321 and the second piezoelectric element 3322) have the same displacement direction.

[0078] [Third aspect] The third aspect is characterized in that in the first or second aspect, the multiple actuators (for example, a first piezoelectric element 3321 and a second piezoelectric element 3322) are arranged in series in the liquid ejection direction.

[0079] According to the first to third aspects, it is possible to provide a liquid ejection head that can reduce the load on the piezoelectric element and ensure a sufficient life span.

[0080] [Fourth aspect] The fourth aspect is characterized in that in any one of the first to third aspects, the multiple actuators (for example, the first piezoelectric element 3321 and the second piezoelectric element 3322) are not always driven simultaneously.

[0081] [Fifth aspect] The fifth aspect is characterized in that in any one of the first to fourth aspects, the plurality of actuators (for example, the first piezoelectric element 3321 and the second piezoelectric element 3322) are alternately driven.

[0082] [Sixth aspect] The sixth aspect is characterized in that in any of the first to fifth aspects, the multiple actuators (e.g., the first piezoelectric element 3321 and the second piezoelectric element 3322) are driven by repeatedly switching the actuators every predetermined number of drives.

[0083] [Seventh aspect] The seventh aspect is characterized in that, in any of the first to sixth aspects, when the applied voltage to the actuator (e.g., the piezoelectric element 332) required to open and close the liquid outlet (e.g., the nozzle 302) is Vx, the multiple actuators (e.g., the first piezoelectric element 3321 and the second piezoelectric element 3322) are each driven with a voltage of Vx / Na (where Na is the number of actuators) and at the same period.

[0084] [Eighth aspect] The eighth aspect is characterized in that, in any of the first to seventh aspects, when the displacement amount of the valve body (e.g., needle valve 331) required to open and close the liquid outlet (e.g., nozzle 302) is x, the multiple actuators (e.g., first piezoelectric element 3321 and second piezoelectric element 3322) are each driven with a displacement amount of x / Na (where Na is the number of actuators) and at the same period.

[0085] According to the fourth to eighth aspects, the load applied to the actuator alone can be reduced.

[0086] [Ninth aspect] A ninth aspect is the seventh aspect, characterized in that the applied voltage Vx is variable according to input data (for example, image data).

[0087] [Tenth aspect] A tenth aspect is the eighth aspect, characterized in that the displacement amount x is variable according to input data (for example, image data).

[0088] According to the ninth and tenth aspects, it is possible to flexibly deal with the size of droplets to be discharged. [Explanation of symbols]

[0089] 300 Liquid ejection head 301 Nozzle plate 302 Nozzle (liquid outlet) 310 Housing 312 Flow Path 330 Liquid Dispensing Module 331 Needle valve (valve body) 332 Piezoelectric element (actuator) 3321 First Piezoelectric Element 3322 Second Piezoelectric Element 333 Retaining member [Prior art documents] [Patent documents]

[0090] [Patent Document 1] JP 2010-241003 A

Claims

1. a liquid ejection port for ejecting liquid; a flow path communicating with the liquid ejection port; a valve body that opens and closes the liquid discharge port; an actuator for driving the valve body; a valve body for opening the liquid ejection port and ejecting the liquid from the liquid ejection port, the valve body being configured to open the liquid ejection port and eject the liquid from the liquid ejection port while the valve body is opening the liquid ejection port, A plurality of actuators are provided for each of the valve bodies; The liquid ejection head according to claim 1, wherein the plurality of actuators are not driven simultaneously.

2. A liquid ejection port for ejecting liquid; a flow path communicating with the liquid ejection port; a valve body that opens and closes the liquid discharge port; an actuator for driving the valve body; a valve body for opening the liquid ejection port and ejecting the liquid from the liquid ejection port, the valve body being configured to open the liquid ejection port and eject the liquid from the liquid ejection port while the valve body is opening the liquid ejection port, A plurality of actuators are provided for each of the valve bodies; A liquid ejection head, characterized in that the plurality of actuators are alternately driven.

3. A liquid ejection port for ejecting a liquid; a flow path communicating with the liquid ejection port; a valve body that opens and closes the liquid discharge port; an actuator for driving the valve body; a valve body for opening the liquid ejection port and ejecting the liquid from the liquid ejection port, the valve body being configured to open the liquid ejection port and eject the liquid from the liquid ejection port while the valve body is opening the liquid ejection port, A plurality of actuators are provided for each of the valve bodies; The liquid ejection head is characterized in that the plurality of actuators are driven by repeatedly switching the actuators every predetermined number of drives.

4. A liquid ejection port for ejecting a liquid; a flow path communicating with the liquid ejection port; a valve body that opens and closes the liquid discharge port; an actuator for driving the valve body; a liquid ejection head configured to eject liquid supplied to the flow path from the liquid ejection port while the valve body is opening the liquid ejection port, A plurality of actuators are provided for each of the valve bodies; A liquid ejection head characterized in that, when the applied voltage to the actuator required to open and close the liquid ejection port is Vx, the multiple actuators are each driven at a voltage of Vx / Na (where Na is the number of actuators) and with the same period.

5. A liquid ejection port for ejecting a liquid; a flow path communicating with the liquid ejection port; a valve body that opens and closes the liquid discharge port; an actuator for driving the valve body; a liquid ejection head configured to eject liquid supplied to the flow path from the liquid ejection port while the valve body is opening the liquid ejection port, A plurality of actuators are provided for each of the valve bodies; a liquid ejection head characterized in that, when the displacement amount of the valve body required to open and close the liquid ejection port is x, the plurality of actuators are each driven with a displacement amount of x / Na (where Na is the number of actuators) and at the same period.

6. A liquid ejection head as described in any one of claims 1 to 5, characterized in that the multiple actuators have the same displacement direction.

7. A liquid ejection head as described in any one of claims 1 to 6, characterized in that the multiple actuators are arranged in series in the ejection direction of the liquid.

8. The liquid ejection head according to claim 4, wherein the applied voltage Vx is variable in response to input data.

9. The liquid ejection head according to claim 5, wherein the displacement amount x is variable in response to input data.

10. A liquid ejection head as described in any one of claims 1 to 9, characterized in that liquid in a pressurized state is supplied to the flow path.

11. A liquid ejection device comprising a liquid ejection head described in any one of claims 1 to 10.

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