WO2023007285A1

WO2023007285A1 - Liquid discharge head and liquid discharge apparatus

Info

Publication number: WO2023007285A1
Application number: PCT/IB2022/056315
Authority: WO
Inventors: Keitaroh Sakai
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2021-07-29
Filing date: 2022-07-08
Publication date: 2023-02-02
Anticipated expiration: 2024-01-29

Abstract

A liquid discharge head (300) includes a nozzle member (301) having a nozzle (302), a valve (331) that opens and closes the nozzle, an actuator (332), an elastic member (333) holding the actuator, and a damper (334) between the elastic member and the actuator. The elastic member is elastically deformable in response to driving of the actuator to transmit a driving force of the actuator to the valve.

Description

[DESCRIPTION]

[Title of Invention]

LIQUID DISCHARGE HEAD AND LIQUID DISCHARGE APPARATUS [Technical Field]

[0001]

Embodiments of the present disclosure relate to a liquid discharge head and a liquid discharge apparatus.

[Background Art]

[0002]

PTL 1 discloses a liquid discharge head that pressurizes a discharge liquid to be discharged from a nozzle and supplies the discharge liquid to a cavity communicating with the nozzle. The liquid discharge head includes a pin that closes the nozzle, an actuator that causes the pin to contact and separate from the nozzle, and a controller that controls the actuator. The discharge liquid is discharged from the nozzle as liquid droplets only while the pin is separated from the nozzle.

With such a configuration, a load may be applied to the actuator and may damage the liquid discharge head.

[Citation List]

[Patent Literature]

[0003]

[PTL 1]

Japanese Unexamined Patent Application Publication No. 2010-241003 [Summary of Invention]

[Technical Problem]

[0004]

An object of the present disclosure is to provide a liquid discharge head that reduces a load applied to an actuator and has a sufficient lifetime.

[Solution to Problem]

[0005]

A liquid discharge head includes a nozzle member having a nozzle, a valve that opens and closes the nozzle, an actuator, an elastic member holding the actuator, and a damper between the elastic member and the actuator. The elastic member is elastically deformable in response to driving of the actuator to transmit a driving force of the actuator to the valve. [Advantageous Effects of Invention]

[0006]

According to the present disclosure, the liquid discharge head can be provided that reduces a load applied to the actuator and has a sufficient lifetime.

[Brief Description of Drawings]

[0007] A more complete appreciation of the embodiments and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings [FIG. 1]

FIG. 1 is a schematic perspective view of a liquid discharge head according to an embodiment of the present disclosure.

[FIG. 2]

FIG. 2 is an overall cross-sectional view of the liquid discharge head.

[FIG. 3]

FIG. 3 is a schematic cross-sectional view of one liquid discharge module of the liquid discharge head.

[FIG. 4]

FIG. 4 is a schematic enlarged view of a tip of a needle valve of the liquid discharge module. [FIG. 5]

FIG. 5 is a schematic cross-sectional view of a damper of the liquid discharge module according to another embodiment of the present disclosure.

[FIG. 6]

FIG. 6 is a schematic enlarged view of the tip of the needle valve according to a modification of the present embodiment.

[FIGS. 7 A and 7B]

FIGS. 7A and 7B are schematic cross-sectional views of the liquid discharge module of the liquid discharge head according to yet another embodiment of the present disclosure.

[FIG. 8]

FIG. 8 is a schematic perspective view of a liquid discharge apparatus according to embodiments of the present disclosure.

[FIG. 9]

FIG. 9 is a schematic perspective view of a carriage of the liquid discharge apparatus in FIG.

8

The accompanying drawings are intended to depict example embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

[Description of Embodiments]

[0008]

In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result. Referring now to the drawings, embodiments of the present disclosure are described below.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0009]

Embodiments of the present disclosure are described below with reference to the drawings. FIG. 1 is a schematic perspective view of a liquid discharge head 300 according to an embodiment of the present disclosure.

[0010]

The liquid discharge head 300 includes a housing 310, a connector 350, a supply port 311, and a collection port 313. The housing 310 is made of a metal material or a resin material. The connector 350 is a terminal for transmitting an electrical signal and attached to an upper portion of the housing 310.

[0011]

The supply port 311 and the collection port 313 are disposed on the left and right sides of the housing 310 in FIGS. 1 and 2. Fiquid is supplied to the liquid discharge head 300 through the supply port 311, and the liquid is drained from the liquid discharge head 300 through the collection port 313.

[0012]

FIG. 2 is a cross-sectional view of the liquid discharge head 300 according to the present embodiment. This cross-sectional view is taken along line A-A in FIG. 1 as viewed in the direction indicated by arrows in FIG. 1.

[0013]

The housing 310 is provided with the connector 350, which transmits an electric signal, at an upper portion thereof and holds a nozzle plate 301, which has nozzles 302 for discharging liquid, at a lower portion thereof in FIG. 2.

The housing 310 includes a channel 312 through which the liquid is fed from the supply port 311 to the collection port 313 above the nozzle plate 301. The nozzle plate 301 is an example of a “nozzle member.”

[0014]

The liquid discharge head 300 includes liquid discharge modules 330, which are described in detail later, to discharge liquid in the channel 312 from the nozzles 302. The liquid discharge modules 330 are disposed between the supply port 311 and the collection port 313. Each of the liquid discharge modules 330 faces the corresponding nozzle 302 of the nozzle plate 301. In the present embodiment, the eight liquid discharge modules 330 correspond to the eight nozzles 302 arranged in a row, respectively.

[0015]

The number and an arrangement of the nozzles 302 and the liquid discharge modules 330 are not limited to eight as described above. For example, the number of the nozzles 302 and the liquid discharge modules 330 may be nine or more, or one rather than plural. Further, the nozzles 302 and the liquid discharge modules 330 may be arranged in multiple rows instead of one row.

[0016]

With the above-described configuration, pressurized liquid is taken into the supply port 311 from the outside of the liquid discharge head 300, fed in the direction indicated by arrow al in FIG. 2, and supplied to the channel 312. The liquid supplied from the supply port 311 is fed through the channel 312 in the direction indicated by arrow a2 in FIG. 2. Then, the liquid that is not discharged from the nozzles 302 arranged along the channel 312 is drained through the collection port 313 in the direction indicated by arrow a3 in FIG. 2.

[0017]

The liquid discharge 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 restraint 314 at a position facing an upper end of the piezoelectric element 332 in FIG. 2. The restraint 314 is in contact with the upper end of the piezoelectric element 332 to define a fixed point of the piezoelectric element 332. The needle valve 331 is an example of a valve, and the piezoelectric element 332 is an example of an actuator.

[0018]

In the above-described configuration, as the piezoelectric element 332 operates to displace the needle valve 331 upward in FIG. 2, the nozzle 302 that has been closed by the needle valve 331 is opened to discharge liquid from the nozzle 302. As the piezoelectric element 332 operates to displace the needle valve 331 downward in FIG. 2, a tip of the needle valve 331 comes into contact with the nozzle 302 to close the nozzle 302 so that liquid is not discharged from the nozzle 302.

[0019]

The liquid discharge head 300 may temporarily stops draining liquid from the collection port 313 while discharging the hquid from the nozzles 302 to prevent a decrease in a discharge efficiency from the nozzle 302. Next, the configuration of the liquid discharge module 330 is described in detail.

[0020]

FIG. 3 is a schematic cross-sectional view of one liquid discharge module 330 of the liquid discharge head 300.

[0021]

As described above, the liquid discharge module 330 includes the needle valve 331 that opens and closes the nozzle 302 and the piezoelectric element 332. The nozzle plate 301 is joined to the housing 310. Further, the channel 312 is shared with the multiple liquid discharge modules 330 in the housing 310 (see FIG. 2).

[0022]

As illustrated in FIG. 4, the tip of the needle valve 331 faces the nozzle 302 of the nozzle plate 301. When the tip of the needle valve 331 contacts the nozzle plate 301, the nozzle 302 is closed. An elastic body 331a may be attached to the tip of the needle valve 331 to more reliably close the nozzle 302. The liquid discharge module 330 includes a bearing 321 and a seal 315. The bearing 321 is disposed between the needle valve 331 and the housing 310.

The seal 315 such as an O-ring is disposed between the bearing 321 and the needle valve 331. [0023]

The housing 310 defines a space 322 therein, and a spring frame 333 is held in the space 322. The spring frame 333 includes a needle -valve holding portion 333a, a frame portion 333b, a restraint contact portion 333c, and an expansion portion 333d, and defines a space 333e. The needle-valve holding portion 333a holds a rear end of the needle valve 331. A part of the restraint contact portion 333c is in contact with the restraint 314 to form the fixed point with the restraint 314 so that the spring frame 333 does not move upward. The piezoelectric element 332 is held in the space 333e of the spring frame 333.

[0024]

With the above-described configuration, the needle valve 331 and the piezoelectric element 332 are coaxially arranged by the spring frame 333, that is, arranged in series in a direction in which liquid is discharged. The spring frame 333 is an example of an “elastic member,” and the needle-valve holding portion 333a is an example of a “valve holder.”

[0025]

The piezoelectric element 332 moves the needle valve 331 in a direction to open the nozzle 302 when a voltage is applied by a voltage application unit. Accordingly, when no voltage is applied to the piezoelectric element 332, the needle valve 331 closes the nozzle 302. Thus, even if the pressurized liquid is supplied to the channel 312, the liquid is not discharged from the nozzle 302.

[0026]

The spring frame 333 holds the piezoelectric element 332. When the voltage application unit applies a voltage to the piezoelectric element 332, the piezoelectric element 332 contracts. When the piezoelectric element 332 contracts, the expansion portion 333d is elastically deformed to absorb the contraction of the piezoelectric element 332, and the needle -valve holding portion 333a secured to one end of the piezoelectric element 332 is pulled toward the other end of the piezoelectric element 332 (upward in FIG. 3). Thus, the spring frame 333 is elastically deformable in response to the driving of the piezoelectric element 332, and transmits a driving force of the piezoelectric element 332 to the needle valve 331. As a result, the needle valve 331 is separated from the nozzle 302 to open the nozzle 302, and the liquid discharge head 300 discharges the pressurized liquid supplied into the channel 312 from the nozzle 302.

[0027]

On the other hand, when the voltage application unit stop applying the voltage to the piezoelectric element 332, the piezoelectric element 332 expands, causing the needle valve 331 to close the nozzle 302. Accordingly, the liquid discharge head 300 stops discharging the liquid from the nozzle 302. The voltage applied to the piezoelectric element 332 and the timing of applying the voltage are controlled to cause the liquid discharge head 300 to discharge the liquid from the nozzles 302. In the present embodiment, the spring frame 333 applies about 50% of the driving force of the piezoelectric element 332 to the piezoelectric element 332 as pressurization, and sandwiches the piezoelectric element 332 at both ends in the longitudinal direction (that is, the vertical direction in FIG. 3, which is the expansion and contraction direction of the piezoelectric element 332).

[0028]

In another embodiment, the piezoelectric element 332 may move the needle valve 331 in a direction to close the nozzle 302 when a voltage is applied. In this case, when the voltage application unit applies a voltage to the piezoelectric element 332, the piezoelectric element 332 expands, causing the needle valve 331 to close the nozzle 302, and when the voltage application unit stop applying the voltage to the piezoelectric element 332, the piezoelectric element 332 contracts, causing the needle valve 331 to open the nozzle 302. Accordingly, the liquid discharge head 300 discharges the pressurized liquid supplied into the channel 312 from the nozzle 302 when no voltage is applied.

[0029]

In the present embodiment, the spring frame 333 as the elastic member has a one-piece body including the needle-valve holding portion 333a, the frame portion 333b, the restraint contact portion 333c, and the expansion portion 333d, but a portion of the body may be replaced with a separate component. For example, the expansion portion 333d may be a spring, and the spring may be attached to the frame portion 333b.

[0030]

The liquid discharge module 330 includes a damper 334 between the piezoelectric element 332 and one (inner) end of the spring frame 333 opposite to the other end where the needle- valve holding portion 333a is disposed. In the present embodiment, the restraint contact portion 333c is disposed at the one end. The damper 334 is made of, for example, a silicon sheet or a rubber material having high attenuation property. The damper 334 attenuates the driving force of the piezoelectric element 332 and transmits the driving force to the elastic member (i.e., the spring frame 333) and the needle valve 331 coupled to the spring frame 333. The driving force is generated by the expansion or contraction of the piezoelectric element 332 when a voltage is applied thereto. Accordingly, overshoot of the piezoelectric element 332 is reduced.

[0031]

The overshoot of the piezoelectric element 332 is a phenomenon in which the piezoelectric element 332 momentarily expands or contracts by an amount larger than desired when a voltage is applied to the piezoelectric element 332. When the piezoelectric element 332 expands or contracts by a large amount, for example, several pm or more to largely move the needle valve 331, the piezoelectric element 332 may excessively expand or contract, and the laminated structure thereof may be destroyed, thereby damaging the piezoelectric element 332. In the present embodiment, the spring frame 333 sandwiches the piezoelectric element 332 at both ends in the longitudinal direction, but the pressurization of the spring frame 333 to the piezoelectric element 332 may not sufficiently prevent the overshoot of the piezoelectric element 332.

[0032]

Therefore, as described above, in the present embodiment, the liquid discharge module 330 further includes the damper 334 between the piezoelectric element 332 and one end of the spring frame 333 opposite to the other end where the needle-valve holding portion 333a is disposed. The damper 334 attenuates the displacement of the piezoelectric element 332.

More specifically, the damper 334 prevents the rapid displacement of the piezoelectric element 332 such as the overshoot. Even when the piezoelectric element 332 is driven, for example, at a high frequency of several kHz or more to expand or contract by a large amount of several pm or more, the damper 334 prevents the overshoot of the piezoelectric element 332.

[0033]

As illustrated in FIG. 5, the damper 334 may be disposed between the piezoelectric element 332 and one end of the spring frame 333 where the needle-valve holding portion 333a is disposed. In FIG. 5, the damper 334 has an external shape fittable into the space 333e of the spring frame 333 and has an internal shape into which the piezoelectric element 332 is fittable. Note that the damper 334 may not have a shape that fits to both the space 333e and the piezoelectric element 332 as described above, and may have a shape that fits into either one of the space 333e and the piezoelectric element 332. This configuration prevents unnecessary movements of the damper 334 and the piezoelectric element 332 in directions other than the thrust direction during the operation of the needle valve 331, and more effectively prevents ringing of the piezoelectric element 332. Further, the damper 334 may be disposed at both ends of the spring frame 333 where the restraint contact portion 333c is disposed and the needle-valve holding portion 333a is disposed.

[0034]

The above-described configuration prevents the damage of the piezoelectric element 332 due to the ringing because the damper 334 prevents the overshoot of the piezoelectric element 332 even when the piezoelectric element 332 is driven at a high stroke and a high frequency. As a result, the lifetime of the piezoelectric element 332 is extended.

[0035]

As described above, the liquid discharge head 300 according to the present embodiment includes the nozzle plate 301 having the nozzle 302, the needle valve 331 that opens and closes the nozzle 302, the piezoelectric element 332, the spring frame 333 holding the piezoelectric element 332, and the damper 334 between the spring frame 333 and the piezoelectric element 332. The spring frame 333 is elastically deformable in response to the driving of the piezoelectric element 332 to transmit the driving force of the piezoelectric element 332 to the needle valve 331.

[0036] As described above, the spring frame 333 includes the needle-valve holding portion 333a holding the needle valve 331, and the damper 334 is disposed between the piezoelectric element 332 and one end of the spring frame 333 opposite to the other end where the needle- valve holding portion 333a is disposed (in the present embodiment, the restraint contact portion 333c is disposed at the one end).

[0037]

Further, as described above, the spring frame 333 includes the needle-valve holding portion 333a holding the needle valve 331, and the damper 334 is disposed between the piezoelectric element 332 and one end of the spring frame 333 where the needle-valve holding portion 333a is disposed.

[0038]

Accordingly, the liquid discharge head 300 can be provided that reduces a load applied to the piezoelectric element 332 and has a sufficient lifetime.

[0039]

As described above, the spring frame 333 has the space 333e in which the piezoelectric element 332 is held, and the damper 334 is disposed in the space 333e and has a shape fittable into the space 333e.

[0040]

This configuration prevents unnecessary movements of the damper 334 in directions other than the thrust direction during the operation of the needle valve 331, and enhances the effect of preventing the ringing of the piezoelectric element 332.

[0041]

FIG. 6 is a schematic enlarged view of the tip of the needle valve 331 according to a modification of the present embodiment.

[0042]

This modification is different from the configuration illustrated in FIG. 4 in that the nozzle plate 301 has a recess 301a. That is, the nozzle plate 301 has the recess 301a at the position where the nozzle 302 and the needle valve 331 face each other so that the tip of the needle valve 331 fits into the recess 301a.

[0043]

The above-described configuration prevents the ringing in the horizontal direction generated by an impact when the needle valve 331 contacts the nozzle 302 in the operation of closing the nozzle 302.

[0044]

As described above, in the present embodiment, the nozzle plate 301 has the recess 301a into which the needle valve 331 is fittable at the position where the nozzle 302 and the needle valve 331 face each other.

[0045] As a result, when the nozzle 302 is closed, the ringing in the lateral direction, which is caused by an impact due to contact between the needle valve 331 and the nozzle 302, can be prevented.

[0046]

Next, another embodiment is described with reference to FIGS. 7A and 7B. FIGS. 7A and 7B are schematic cross-sectional views of the liquid discharge module 330 of the liquid discharge head 300 according to another embodiment of the present disclosure. FIG. 7A is a cross- sectional view of the liquid discharge module 330 with the nozzle 302 closed, and FIG. 7B is a cross-sectional view of the liquid discharge module 330 with the nozzle 302 opened.

[0047]

This embodiment is different from the above-described embodiment in that a reverse spring mechanism 335 as an example of a transmission mechanism is disposed between the needle valve 331 and the spring frame 333. In this embodiment, the piezoelectric element 332 expands when a voltage is applied.

[0048]

The reverse spring mechanism 335 is an elastic body formed of rubber, soft resin, or thin metal plate which is appropriately processed to be deformable. The reverse spring mechanism 335 includes a deformable portion 335a, a secured portion 335b, a guide portion 335c, and a bent side 335d.

[0049]

The deformable portion 335a has a substantially trapezoidal cross-section. The deformable portion 335a contacts a base end (upper end in FIG. 7A) of the needle valve 331.

[0050]

The secured portion 335b is secured to the deformable portion 335a and the inner wall of the housing 310.

[0051]

The guide portion 335c is held by the needle-valve holding portion 333a of the spring frame 333 and couples the secured portion 335b and the spring frame 333.

[0052]

The bent side 335d couples the long side (corresponding to the lower base of the trapezoid) of the trapezoidal deformable portion 335a and the secured portion 335b.

[0053]

The reverse spring mechanism 335 has the above-described configuration. The piezoelectric element 332 expands when a predetermined voltage is applied to the piezoelectric element 332. When the piezoelectric element 332 expands, the needle-valve holding portion 333a of the spring frame 333 moves toward the nozzle 302, thereby pushing the guide portion 335c toward the nozzle 302 (in the direction indicated by arrow a in FIG. 7B).

[0054]

This pushing force causes the deformable portion 335a to be retracted in the direction away from the nozzle 302 (direction indicated by arrow b in FIG. 7B), thereby moving the needle valve 331 by a distance d illustrated in FIG. 7B. That is, the reverse spring mechanism 335 converts an expanding force of the piezoelectric element 332 and the spring frame 333 into a retracting force to retract the needle valve 331, and then transmits the retracting force to the needle valve 331.

[0055]

In this embodiment, when a voltage is applied to the piezoelectric elements 332, the piezoelectric element 332 expands, and accordingly the needle valve 331 opens the nozzle 302. As a result, the liquid discharge head 300 discharges liquid droplets D2 from the nozzle 302.

[0056]

As described above, in this embodiment, the reverse spring mechanism 335 is disposed between the needle valve 331 and the piezoelectric element 332. The reverse spring mechanism 335 converts the expanding force of the piezoelectric element 332 and the spring frame 333 into the retracting force to retract the needle valve 331, which acts in the direction opposite to the expanding force, and then transmits the retracting force to the needle valve 331.

[0057]

Also in this embodiment, the liquid discharge head 300 can be provided that reduces a load applied to the piezoelectric element 332 and has a sufficient lifetime.

[0058]

FIG. 8 is a schematic perspective view of a printing apparatus 1000 as an example of a liquid discharge apparatus according to the embodiments of the present disclosure.

[0059]

The printing apparatus 1000 is installed so as to face an object 100 on which images are drawn. The printing apparatus 1000 includes an X-axis rail 101, a Y-axis rail 102 intersecting the X-axis rail 101, and a Z-axis rail 103 intersecting the X-axis rail 101 and the Y-axis rail 102.

[0060]

The Y-axis rail 102 movably holds the X-axis rail 101 in the Y direction (positive and negative directions). The X-axis rail 101 movably holds the Z-axis rail 103 in the X direction (positive and negative directions). The Z-axis rail 103 movably holds a carriage 1 in the Z direction (positive and negative directions).

[0061]

Further, the printing apparatus 1000 includes a first Z-direction driver 92 and an X-direction driver 72. The first Z-direction driver 92 moves the carriage 1 in the Z direction along the Z- axis rail 103. The X-direction driver 72 moves the Z-axis rail 103 in the X direction along the X-axis rail 101. The printing apparatus 1000 further includes a Y-direction driver 82 that moves the X-axis rail 101 in the Y direction along the Y-axis rail 102. Further, the printing apparatus 1000 includes a second Z-direction driver 93 that moves a head holder 70 relative to the carriage 1 in the Z direction. [0062]

The printing apparatus 1000 described above discharges ink from the liquid discharge head 300 (see FIG. 9) mounted on the head holder 70 while moving the carriage 1 in the X direction, the Y direction, and the Z direction, thereby drawing images on the object 100. The ink is an example of liquid. The movement of the carriage 1 and the head holder 70 in the Z direction is not necessarily parallel to the Z direction, and may be an oblique movement including at least a Z direction component. The X-axis, Y-axis, and Z-axis rails 101, 102, and 103 and the X-direction, Y-direction, first Z-direction, and second Z-direction drivers 72, 82, 92, and 93 are examples of a “moving unit.”

[0063]

Although the object 100 is flat in FIG. 8, the object 100 may have a surface shape which is nearly vertical, a curved surface with the large radius of curvature, or a surface having a slight unevenness, such as a body of a car, a truck, or an aircraft.

[0064]

Next, the configuration of the carriage 1 is described.

[0065]

FIG. 9 is an overall perspective view of the carriage 1 of the printing apparatus 1000 illustrated in FIG. 8, in which the carriage 1 is viewed from the object 100.

[0066]

The carriage 1 includes the head holder 70. The carriage 1 is movable in the Z-direction (positive and negative directions) along the Z-axis rail 103 by driving force of the first Z- direction driver 92 as illustrated in FIG. 8.

[0067]

The head holder 70 is movable in the Z-direction (positive and negative directions) with respect to the carriage 1 by driving force of the second Z-direction driver 93 as illustrated in FIG. 8. The head holder 70 includes a head fixing plate 70a to attach the liquid discharge head 300 to the head holder 70. In the present embodiment, six liquid discharge heads 300a to 300f are attached to the head fixing plate 70a and stacked one on another. Each of the liquid discharge heads 300a to 300f is the liquid discharge head 300 described with reference to FIGS. 1 to 6. In the following description, these liquid discharge heads 300a to 300f are collectively referred to as the liquid discharge heads 300.

[0068]

Each of the liquid discharge heads 300 includes multiple nozzles 302. The number and type of ink used in the liquid discharge heads 300 is not particularly limited, and the ink may be different color for each of the liquid discharge heads 300 or may be the same color for all the liquid discharge heads 300. For example, when the printing apparatus 1000 is a coating apparatus using a single color, the inks used in the liquid discharge heads 300 may be the same color. The number of the liquid discharge heads 300 is not limited to six, and may be seven or more, or less than six.

[0069] The liquid discharge heads 300 are secured to the head fixing plate 70a such that a nozzle row of each liquid discharge head 300 intersects the horizontal plane (i.e., X-Z plane) and the plurality of nozzles 302 is obliquely arrayed with respect to the X-axis as illustrated in FIG. 9. Thus, the liquid discharge head 300 discharges ink from the nozzle 302 in a direction (positive Z direction in the present embodiment) intersecting the direction of gravity to form a desired image on the object 100.

[0070]

Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant.

[0071]

These liquids can be used for, e.g., inkjet ink, coating paint, surface treatment solution, a liquid for forming components of electronic element or light-emitting element or a resist pattern of electronic circuit, or a material solution for three-dimensional fabrication.

[0072]

The liquid discharge apparatus according to the present embodiment is not limited to the printing apparatus 1000 described above. For example, the liquid discharge head according to the above-described embodiments of the present disclosure may be attached to a tip of a robot arm of a multi-articulated robot that can freely move like a human arm by a plurality of joints. The liquid discharge apparatus is not limited to a configuration in which the liquid discharge head is moved relative to an object. A configuration in which the liquid discharge head and the object are movable relative to each other, for example, the object is moved relative to the liquid discharge head is applicable.

[0073]

The above-described embodiments are one of examples and, for example, the following Aspects 1 to 6 of the present disclosure can provide the following advantages.

[0074]

Aspect 1

According to Aspect 1, a liquid discharge head (e.g., the liquid discharge head 300) includes a nozzle member (e.g., the nozzle plate 301) having a nozzle (e.g., the nozzle 302), a valve (e.g., the needle valve 331) that opens and closes the nozzle, an actuator (e.g., the piezoelectric element 332), an elastic member (e.g., the spring frame 333) holding the actuator, and a damper (e.g., the damper 334) between the elastic member and the actuator. The elastic member is elastically deformable in response to driving of the actuator to transmit a driving force of the actuator to the valve.

[0075]

Aspect 2 According to Aspect 2, in Aspect 1, the elastic member (e.g., the spring frame 333) includes a valve holder (e.g., the needle-valve holding portion 333a) holding the valve (e.g., the needle valve 331), and the damper (e.g., the damper 334) is disposed between the actuator (e.g., the piezoelectric element 332) and one end of the elastic member opposite to another end where the valve holder is disposed.

[0076]

Aspect 3

According to Aspect 3, in Aspect 1 or 2, the elastic member (e.g., the spring frame 333) includes a valve holder (e.g., the needle-valve holding portion 333a) holding the valve (e.g., the needle valve 331), and the damper (e.g., the damper 334) is disposed between the actuator (e.g., the piezoelectric element 332) and one end of the elastic member where the valve holder is disposed.

[0077]

According to Aspects 1 to 3, the liquid discharge head can be provided that reduces a load applied to the actuator and has a sufficient lifetime.

[0078]

Aspect 4

According to Aspect 4, in any one of Aspects 1 to 3, the elastic member (e.g., the spring frame 333) has a space (e.g., the space 333e) in which the actuator (e.g., the piezoelectric element 332) is held, and the damper (e.g., the damper 334) is disposed in the space and has a shape fittable into the space.

[0079]

According to Aspect 4, unnecessary movements of the damper 334 in directions other than the thrust direction is prevented during the operation of the valve, and the effect of preventing the ringing is enhanced.

[0080]

Aspect 5

According to Aspect 5, in any one of Aspects 1 to 4, the nozzle member (e.g., the nozzle plate 301) has a recess (e.g., the recess 301a) into which the valve (e.g., the needle valve 331) is fittable at a position where the nozzle (e.g., the nozzle 302) and the valve face each other. [0081]

According to Aspect 5, when the nozzle is closed, the ringing in the lateral direction, which is caused by an impact due to contact between the valve and the nozzle, can be prevented.

[0082]

Aspect 6

According to Aspect 6, in any one of the Aspects 1 to 5, a transmission mechanism (e.g., the reverse spring mechanism 335) is disposed between the valve (e.g., the needle valve 331) and the actuator (e.g., the piezoelectric element 332). The transmission mechanism converts an expanding force of the actuator and the elastic member (e.g., the spring frame 333) into a retracting force that retracts the valve in a direction opposite to the expanding force and transmits the retracting force to the valve.

[0083]

According to Aspect 6, the liquid discharge head can be provided that reduces a load applied to the actuator and has a sufficient lifetime.

[0084]

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention [0085]

This patent application is based on and claims priority to Japanese Patent Application Nos. 2021-123780, filed on July 29, 2021 and 2022-072936, filed on April 27, 2022, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.

[Reference Signs List]

[0086]

300 Liquid discharge head

301 Nozzle plate (an example of a nozzle member)

302 Nozzle

330 Liquid discharge module

331 Needle valve (an example of a valve)

332 Piezoelectric element (an example of an actuator)

333 Spring frame (an example of an elastic member)

334 Damper

335 Reverse spring mechanism (an example of a transmission mechanism)

Claims

[CLAIMS]

[Claim 1]

A liquid discharge head comprising: a nozzle member having a nozzle; a valve configured to open and close the nozzle; an actuator; an elastic member holding the actuator, the elastic member elastically deformable in response to driving of the actuator to transmit a driving force of the actuator to the valve; and a damper between the elastic member and the actuator.

[Claim 2]

The liquid discharge head according to claim 1 , wherein the elastic member includes a valve holder holding the valve, and wherein the damper is disposed between the actuator and one end of the elastic member opposite to another end where the valve holder is disposed.

[Claim 3]

The liquid discharge head according to claim 1 or 2, wherein the elastic member includes a valve holder holding the valve, and wherein the damper is disposed between the actuator and one end of the elastic member where the valve holder is disposed.

[Claim 4]

The liquid discharge head according to any one of claims 1 to 3, wherein the elastic member has a space in which the actuator is held, and wherein the damper is disposed in the space and has a shape fittable into the space.

[Claim 5]

The liquid discharge head according to any one of claims 1 to 4, wherein the nozzle member has a recess into which the valve is fittable at a position where the nozzle and the valve face each other.

[Claim 6]

The liquid discharge head according to any one of claims 1 to 5, further comprising a transmission mechanism between the valve and the actuator, wherein the transmission mechanism is configured to convert an expanding force of the actuator and the elastic member into a retracting force that retracts the valve in a direction opposite to the expanding force and transmit the retracting force to the valve.

[Claim 7]

A liquid discharge apparatus comprising: the liquid discharge head according to any one of claims 1 to 6, configured to discharge a liquid from the nozzle to an object; and a moving unit configured to relatively move the liquid discharge head and the object.