WO2024150061A1

WO2024150061A1 - Liquid discharge head and liquid discharge apparatus

Info

Publication number: WO2024150061A1
Application number: PCT/IB2023/063230
Authority: WO
Inventors: Atsushi Takeuchi; Masanori Kusunoki; Yuta KINASE; Naoko Kitaoka
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2023-01-12
Filing date: 2023-12-26
Publication date: 2024-07-18
Anticipated expiration: 2025-07-12
Also published as: JP2024099377A; CN120476046A; EP4648971A1

Abstract

A liquid discharge head includes a plurality of nozzles, a plurality of pressure chambers, a plurality of actuators, a common liquid chamber, and a damper. The plurality of nozzles discharge liquid. Each of the plurality of pressure chambers communicates with a corresponding one of the plurality of nozzles. Each of the plurality of actuators is disposed on a nozzle communication wall of a corresponding one of the plurality of pressure chambers to pressurize liquid in the corresponding one of the plurality of pressure chambers. The common liquid chamber communicates with the plurality of pressure chambers; and a damper disposed at a position facing opening portions of the plurality of pressure chambers, the opening portions facing the common liquid chamber. A minimum distance between the damper and each of the opening portions is equal to or less than a center-to-center distance between adjacent two of the opening portions.

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]

A liquid discharge head has been known that includes a plurality of nozzles for discharging liquid, a plurality of pressure chambers respectively communicating with the plurality of nozzles, a plurality of actuators respectively disposed on nozzle communication walls of the plurality of pressure chambers for pressurizing liquid in the respective pressure chambers, and a common liquid chamber communicating with the plurality of pressure chambers.

[0003]

For example, PTL 1 discloses a liquid discharge head including a nozzle plate (a nozzle communication wall) on which a plurality of nozzles and actuators are formed, a substrate on which a plurality of cylindrical pressure chambers respectively communicating with the plurality of nozzles are formed, and a damper member. The actuators are formed in an annular shape coaxial with the nozzle, and is driven to pressurize the liquid in each pressure chamber. The damper member is an elastic member disposed on a surface opposite to a surface of the substrate on which the nozzle plate is disposed, and a plurality of cylindrical damper chambers having the same inner diameter as each pressure chamber is disposed to face each pressure chamber. A common liquid chamber communicates with each pressure chamber via each damper chamber of the damper member. A pressure wave of the liquid generated by the actuator driving in each pressure chamber is absorbed by elastic deformation of the damper member. Thus, a crosstalk in which the pressure wave propagates to another pressure chamber can be reduced.

[Citation List]

[Patent Literature]

[0004]

[PTL 1]

Japanese Unexamined Patent Application Publication No. 2021-41569 [Summary of Invention] [Technical Problem] [0005]

However, in the liquid discharge head in which each of the actuators is disposed on a nozzle communication wall of a corresponding one of the multiple pressure chambers, the configuration of the related art can reduce crosstalk but may be disadvantageous in that it is difficult to increase the number of nozzles per unit area. [Solution to Problem]

[0006]

To solve the above-described disadvantage, according to an embodiment of the present disclosure, a liquid discharge head includes a plurality of nozzles, a plurality of pressure chambers, a plurality of actuators, a common liquid chamber, and a damper. The plurality of nozzles discharge liquid. Each of the plurality of pressure chambers communicates with a corresponding one of the plurality of nozzles. Each of the plurality of actuators is disposed on a nozzle communication wall of a corresponding one of the plurality of pressure chambers to pressurize liquid in the corresponding one of the plurality of pressure chambers. The common liquid chamber communicates with the plurality of pressure chambers. The damper is disposed at a position facing opening portions of the plurality of pressure chambers, the opening portions facing the common liquid chamber. A minimum distance between the damper and each of the opening portions is equal to or less than a center-to-center distance between adjacent two of the opening portions.

[Advantageous Effects of Invention]

[0007]

According to an embodiment of the present disclosure, in the liquid discharge head in which each of the actuators is disposed on the nozzle communication wall of the corresponding one of the multiple pressure chambers, the number of nozzles per unit area can be increased and crosstalk can be reduced.

[Brief Description of Drawings]

[0008]

A more complete appreciation of embodiments of the present disclosure 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.

[0009]

[Fig. 1]

FIG. 1 is a cross-sectional view schematically illustrating a nozzle vibration type liquid discharge head according to an embodiment of the present disclosure.

[Fig. 2]

FIG. 2 is a perspective view schematically illustrating a nozzle surface of the liquid discharge head of FIG. 1.

[Fig. 3]

FIG. 3 is an enlarged cross-sectional view of a part surrounded by a broken line indicated by a reference sign X in FIG. 1.

[Fig. 4]

FIG. 4 is a plan view schematically illustrating an internal structure of the liquid discharge head of FIG. 1, and is a cross-sectional view taken along a line C-C'.

[Fig. 5] FIG. 5 is a front view schematically illustrating an internal structure of the liquid discharge head of FIG. 1, and is a cross-sectional view taken along a line A- A'.

[Fig. 6]

FIG. 6 is a side view schematically illustrating an internal structure of the liquid discharge head of FIG. 1, and is a cross-sectional view taken along a line B-B'.

[Fig. 7]

FIG. 7 is a graph illustrating a simulation result of a crosstalk reduction effect by a damper. [Fig. 8]

FIG. 8 is a graph illustrating a simulation result of a change rate of the liquid discharge speed when a minimum distance between each opening portion of a plurality of pressure chambers and a damper film is changed.

[Fig. 9]

FIG. 9 is a plan view schematically illustrating an internal structure of a liquid discharge head according to a first modification, and is a cross-sectional view taken along the line C-C'.

[Fig. 10]

FIG. 10 is a side view schematically illustrating an internal structure of the liquid discharge head of FIG. 9, and is a cross-sectional view taken along the line B-B'.

[Fig. 11]

FIG. 11 is a plan view schematically illustrating an internal structure of a liquid discharge head according to a second modification, and is a cross-sectional view taken along a line D- D'.

[Fig. 12]

FIG. 12 is a side view schematically illustrating an internal structure of the liquid discharge head of FIG. 11, and is a cross-sectional view taken along the line B-B'.

[Fig. 13]

FIG. 13 is a plan view schematically illustrating an internal structure of four liquid discharge heads of a head unit according to a third modification, and is a cross-sectional view taken along the line C-C'.

[Fig. 14]

FIG. 14 is a side view schematically illustrating an internal structure of four liquid discharge heads of the head unit of FIG. 13, and is a cross-sectional view taken along the line A-A'. [Fig. 15]

FIG. 15 is a plan view schematically illustrating an internal structure of a liquid discharge head according to a fourth modification, and is a cross-sectional view taken along the line C- C.

[Fig. 16]

FIG. 16 is a front view schematically illustrating an internal structure of the liquid discharge head of FIG. 15, and is a cross-sectional view taken along a line E-E'.

[Fig. 17] FIG. 17 is a side view schematically illustrating an internal structure of the liquid discharge head of FIG. 15, and is a cross-sectional view taken along a line F-F'.

[Fig. 18]

FIG. 18 is a plan view schematically illustrating an internal structure of four liquid discharge heads of a head unit according to a fifth modification, and is a cross-sectional view taken along the line C-C'.

[Fig. 19]

FIG. 19 is a side view schematically illustrating an internal structure of four liquid discharge heads of the head unit of FIG. 18, and is a cross-sectional view taken along the line E-E'.

[Fig. 20]

FIG. 20 is a plan view schematically illustrating an internal structure of a liquid discharge head according to a sixth modification, and is a cross-sectional view taken along the line C-C'. [Fig. 21]

FIG. 21 is a front view schematically illustrating an internal structure of the liquid discharge head of FIG. 20, and is a cross-sectional view taken along a line G-G'.

[Fig. 22]

FIG. 22 is a cross-sectional view schematically illustrating an internal structure of a head unit in which four liquid discharge heads of FIG. 20 are disposed.

[Fig. 23]

FIG. 23 is a plan view schematically illustrating an internal structure of a liquid discharge head according to a seventh modification, and is a cross-sectional view taken along the line C- C'.

[Fig. 24]

FIG. 24 is a front view schematically illustrating an internal structure of the liquid discharge head of FIG. 23, and is a cross-sectional view taken along a line H-H'.

[Fig. 25]

FIG. 25 is a cross-sectional view schematically illustrating an internal structure of a head unit in which four liquid discharge heads of FIG. 23 are disposed.

[Fig. 26]

FIG. 26 is a schematic explanatory view of a printing apparatus according to an embodiment of the present disclosure.

[Fig. 27]

FIG. 27 is a plan explanatory view of an example of a head unit of the printing apparatus of

FIG. 26.

[Fig. 28]

FIG. 28 is an explanatory plan view of a main part of the printing apparatus according to an embodiment of the present disclosure.

[Fig. 29]

FIG. 29 is an explanatory side view of a main part of the printing apparatus of FIG. 28.

[Fig. 30] FIG. 30 is an explanatory plan view of a main part of a liquid discharge unit according to an embodiment of the present disclosure.

[Fig. 31]

FIG. 31 is an explanatory front view of the liquid discharge unit according to an embodiment of the present disclosure.

[0010]

The accompanying drawings are intended to depict embodiments of the present disclosure 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]

[0011]

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. Hereinafter, a liquid discharge head according to an embodiment of the present disclosure provided in a liquid discharge apparatus will be described.

The present disclosure is not limited to the embodiments described below and may be other embodiments than the embodiments described below. The following embodiments may be modified by, for example, addition, modification, or omission within the scope that would be obvious to one skilled in the art. Any aspect having function and effect according to the present disclosure are included within the scope of the present disclosure.

[0012]

The liquid discharge head in the present embodiment is a nozzle vibration type liquid discharge head that discharges liquid in a pressure chamber from a nozzle by varying a pressure in the pressure chamber by the actuators disposed on a nozzle plate having the nozzle. The nozzle vibration type is characterized in that droplets can be splashed with a smaller force than a general unimorph piezo head (that discharges liquid by vibrating a surface of the pressure chamber facing a wall portion (a nozzle communication wall) having a communication port communicating with a nozzle of the pressure chamber), and can achieve power saving of the actuators.

[0013]

When a nozzle density is increased, a space for laying out wirings for voltage application is limited, and it is difficult to construct wirings on a substrate surface. By constructing the wirings and a drive circuit in the substrate, the wirings can be laid out even in a configuration having a high nozzle density. In general, a lead zirconate titanate (PZT) is widely used as a material of a piezoelectric element used as an actuator because of its high piezoelectric characteristics. However, when the piezoelectric membrane is formed on a substrate on which the wirings and the drive circuit are constructed, a PZT membrane formation/crystallization temperature has to be 600°C or higher. Therefore, when the PZT is used as a material of a piezoelectric element, the drive circuit in the substrate and the wirings thereof cannot withstand high temperatures. Therefore, in the configuration in which the wirings and the drive circuit are constructed in the substrate, a piezoelectric material having a lower film formation temperature than the PZT has to be as the piezoelectric material, and a material having lower piezoelectric characteristics than the PZT is necessarily selected. However, since the nozzle vibration type described above has a feature that the droplets can be splashed with a smaller force than that of a general unimorph piezo head, it is possible to discharge the liquid satisfactorily even when a material having lower piezoelectric characteristics than the PZT is selected. Therefore, even a piezoelectric material such as a non-lead material having a low film formation/crystallization temperature but low power can discharge the liquid satisfactorily. As a result, the wirings and the drive circuit can be constructed in the substrate, and the density can be increased. Furthermore, since the nozzle vibration type can reduce a volume of the pressure chamber, the liquid discharge head can be downsized.

[0014]

FIG. 1 is a cross-sectional view schematically illustrating a nozzle vibration type liquid discharge head according to the present embodiment.

FIG. 2 is a perspective view schematically illustrating a nozzle surface of the liquid discharge head according to the present embodiment.

A liquid discharge head 1 includes a nozzle plate 110, a pressure chamber substrate 100, and a common liquid chamber substrate 120. In addition, the liquid discharge head 1 also includes a damper 130, a frame 140, and the like as described later.

[0015]

The nozzle plate 110 has a thin membrane shape and includes a plurality of nozzles 2 for discharging liquid and a piezoelectric elements 5 as an electromechanical transducer element which is an annular actuator arranged around the nozzles 2. The pressure chamber substrate 100 includes a plurality of pressure chambers (also referred to as an individual liquid chamber and a pressurized liquid chamber) 4, each of which communicates with a corresponding one of the plurality of nozzles 2. A nozzle 2 (a vibration membrane 103) is disposed on one side of each pressure chamber 4, and an opening portion 4a of the pressure chamber 4 and the damper 130 are disposed on the opposite side of the pressure chamber 4 to the one side. The common liquid chamber substrate 120 includes a common liquid chamber 3 communicating with the plurality of pressure chambers 4. Electrical connection pads 55 for coupling to electrical components such as an external power supply are disposed at both ends of the liquid discharge head 1.

[0016] FIG. 3 is the enlarged cross-sectional view of the part surrounded by the broken line indicated by the reference sign X in FIG. 1.

The pressure chamber substrate 100 is a silicon on insulator (SOI) substrate, and includes a drive circuit 101 and a wiring portion 102 on a side where the vibration membrane 103 is formed. The drive circuit 101 is a circuit including a transistor, a resistor, and the like. The wiring portion 102 includes a wiring portion for applying a drive waveform to a first electrode 51 and a wiring portion for applying a drive waveform to a second electrode 53. In addition, the wiring portion 102 is electrically coupled to an electrical connection pad 55 via a third contact 7c opened on the vibration membrane 103.

[0017]

The nozzle plate 110 includes a nozzle forming portion (a membrane) 111 in which a plurality of nozzles 2 is formed and which covers the piezoelectric elements 5, and a liquid -repellent membrane 112 is formed on a nozzle surface of the nozzle forming portion 111. In a case where the discharge of the liquid is continued, mist generated at the same time as the discharge adheres to the nozzle surface. When a large amount of the mist adheres to the nozzle surface, there is a possibility that the liquid discharged from the nozzle 2 is affected by the liquid adhering to the nozzle surface and deviates from a desired landing position. By forming the liquid-repellent membrane 112 on the nozzle surface, adhesion of liquid to the nozzle surface can be reduced, and influence of liquid adhered to the nozzle surface on liquid discharged from the nozzle 2 can be reduced.

[0018]

The piezoelectric element 5 of the nozzle plate 110 includes the first electrode 51 (also referred to as a lower electrode), a piezoelectric membrane 52, and the second electrode 53 (also referred to as an upper electrode). The piezoelectric element 5 is covered with a first insulating membrane 8a. In the first insulating membrane 8a, a hole-shaped fourth contact 7d for making electrical connection to the first electrode 51 and a hole-shaped fifth contact 7e for making electrical connection to the second electrode 53 are formed.

[0019]

In the first insulating membrane 8a, a first lead wiring 9a that electrically connects the first electrode 51 of the piezoelectric element 5 and the wiring portion 102 of the pressure chamber substrate 100 and a second lead wiring 9b that electrically connects the second electrode 53 of the piezoelectric element 5 and the wiring portion 102 of the pressure chamber substrate 100 are formed.

[0020]

The first lead wiring 9a is electrode-like coupled to the first electrode 51 via the fourth contact 7d and electrode-like coupled to the wiring portion 102 via the first contact 7a. The second lead wiring 9b is electrode-like coupled to the second electrode 53 via the fifth contact 7e, and electrode-like coupled to the wiring portion 102 via the second contact 7b. The first lead wiring 9a and the second lead wiring 9b are covered with a second insulating membrane 8b. In the present embodiment, the second insulating membrane 8b also covers the piezoelectric element 5, and has a function of protecting the piezoelectric element 5 by preventing moisture entering the nozzle forming portion 111 made of resin from entering the piezoelectric element 5.

[0021]

A lead-out wiring portion may be disposed in each of the first electrode 51 and the second electrode 53, and the lead-out wiring portion may be directly electrode-like coupled to the wiring portion 102 via a contact opened on the vibration membrane. An adhesion improving membrane for securing adhesion to the nozzle forming portion 111 may be formed on the second insulating membrane 8b.

[0022]

The liquid filled in the liquid discharge head 1 enters the nozzle 2 and forms a meniscus in the nozzle. By applying a predetermined drive waveform (a voltage) to each of the electrodes 51 and 53 of the piezoelectric element 5, the piezoelectric membrane 52 vibrates, and the vibration membrane 103 vibrates in a vertical direction in FIG. 3. When the vibration membrane 103 vibrates, a pressure change occurs in the liquid in the pressure chamber, and the liquid is discharged from the nozzle 2.

[0023]

In the liquid discharge head 1 of the present embodiment, a protective membrane 11 as a surface layer that is lyophilic to the liquid ejected by the liquid discharge head 1 and prevents erosion of the liquid is formed on the inner peripheral surface of the nozzle 2, the inner peripheral surface of the pressure chamber 4, and a bottom surface of a common liquid chamber 3. In the present embodiment, the liquid ejected by the liquid discharge head 1 is alkaline, and the pressure chamber substrate 100 and the vibration membrane 103 forming the pressure chamber 4 are made of silicon single crystal and silicon oxide. These materials are vulnerable to alkaline liquids and elute and erode into alkaline solutions. In order to prevent this, the pressure chamber substrate 100 and the vibration membrane 103 can be protected from the liquid by forming the liquid-resistant protective membrane 11 that prevents erosion of the liquid.

[0024]

The pressure chamber 4 and the nozzle 2 are formed by dry etching. When a dry etching gas contains fluorine, a surface membrane containing fluorine is formed on an inner wall surface of the pressure chamber 4 and an inner peripheral surface of the nozzle 2 after etching, and the inner wall surface of the pressure chamber 4 and the nozzle inner peripheral surface have liquid repellency. If the inner peripheral surface of the pressure chamber 4 has liquid repellency, the liquid does not wet-spread on the inner peripheral surface of the pressure chamber 4 during liquid filling. Therefore, the pressure chamber 4 may not be satisfactorily filled with the liquid, and the air bubbles may be generated at corner portions or the like of the pressure chamber 4.

[0025] In the present embodiment, since the protective membrane 11 having lyophilic property is formed on the inner peripheral surface of the pressure chamber 4 and the inner peripheral surface of the nozzle 2, wettability of liquid to the inner peripheral surfaces of the pressure chamber 4 and the nozzle 2 can be improved. The protective membrane 11 merely has to have a lyophilic property to liquid more than a film formation surface of the pressure chamber 4 or the nozzle 2 (a lower layer surface of the protective membrane 11) on which the protective membrane 11 is formed. In a case where the liquid solvent is aqueous, a highly hydrophilic protective membrane is used, and in a case where the liquid solvent is oily, a highly lipophilic protective membrane is used, whereby the highly lipophilic protective membrane 11 can be formed.

[0026]

As described above, by forming the protective membrane 11 having a lyophilic property with respect to the liquid filled in the pressure chamber 4 on the inner peripheral surfaces of the nozzle 2 and the pressure chamber 4, the liquid easily wets and spreads on the inner peripheral surfaces of the pressure chamber 4 and the nozzle 2 during liquid filling. As a result, a filling property of the liquid can be improved, and the pressure chamber 4 and the nozzle 2 can be favorably filled with the liquid without performing pressurization or suction during liquid filling. Therefore, the occurrence of cracks in the vibration membrane 103 during liquid filling can be reduced.

[0027]

Since the liquid solvent of the present embodiment is aqueous, by forming the protective membrane 11 not containing at least fluorine on the inner peripheral surfaces of the pressure chamber 4 and the nozzle 2, lyophilicity can be improved as compared with a surface membrane containing fluorine formed by dry etching. In addition to the above, since this membrane is in direct contact with various liquids, it is desirable to use a material having liquid resistance, for example, an oxide of a metal forming a passivation state. Furthermore, as a method for improving the lyophilicity, a mixture of the metal oxide forming the passivation state with silicon dioxide (SiCh) at a molecular level can also be used. SiCh of the protective membrane 11 has a hydrophilic OH group in which O on the surface is substituted. Thus, hydrophilicity can be further imparted to the protective membrane 11. Examples of the metal of the metal oxide include tantalum (Ta), niobium (Nb), titanium (Ti), zirconium (Zr), hafnium (Hf), and tungsten (W) having high correspondence to the number of oxides. In particular, Zr or Hf having a valence similar to that of SiO2, or Ta having a valence before or after that is particularly desirable.

[0028]

In addition, for example, the protective membrane 11 may have a two-layer structure of a liquid-resistant membrane and a lyophilic membrane. In this case, a liquid-resistant membrane is formed on the inner peripheral surfaces of the nozzle 2 and the pressure chamber 4, and then a lyophilic membrane is formed on the liquid-resistant membrane.

[0029] In the present embodiment, the lyophilic protective membrane 11 is also formed on the surface of the pressure chamber substrate 100 constituting a bottom surface of the common liquid chamber 3 opposite to the film formation surface of the vibration membrane 103, but the protective membrane 11 on this surface may have merely liquid resistance. However, a step of forming the protective membrane 11 on the bottom surface of the common liquid chamber 3 has to be provided separately from a step of forming a lyophilic protective membrane on the nozzle inner peripheral surface and the wall surface of the pressure chamber, and the number of manufacturing steps may increase. In addition, by forming the protective membrane 11 on the bottom surface of the common liquid chamber 3, the liquid easily wets and spreads on the bottom surface of the common liquid chamber 3, so that the filling property of the liquid is also improved. Therefore, it is preferable to form the lyophilic protective membrane 11 also on the surface of the pressure chamber substrate 100 constituting the bottom surface of the common liquid chamber 3 opposite to the film formation surface of the vibration membrane 103.

[0030]

The vibration membrane 103 may be made of at least an insulating material such as SiCh, SiN, a metal oxide, or a resin. However, in order to increase a displacement, a material having a low Young's modulus is desirable, and considering a difference in linear expansion coefficient from the pressure chamber substrate 100, SiCh (silicon dioxide) having a relatively small difference is most desirable as the material of the vibration membrane 103.

[0031]

A first electrode layer 151 and a second electrode layer 153 are desirably made of a metal having low electric resistance and low reactivity, and are desirably made of a metal such as Ir or Mo. As the piezoelectric material of a piezoelectric layer 152, when the drive circuit 101 and the wiring portion 102 are incorporated in the pressure chamber substrate 100 to improve the density as in the present embodiment, a piezoelectric material having a film formation temperature of 450°C or lower is desirable in order not to break them. Examples of the piezoelectric material having a film formation temperature of 450°C or lower include AIN or ScAlN having a piezoelectric constant higher than that of AIN.

[0032]

Further, by using ScAlN as the piezoelectric material, the following advantages can also be obtained. In other words, it is possible to improve the piezoelectric characteristics by aligning a crystal orientation of the piezoelectric membrane 52, but it is necessary to provide an orientation control layer between the vibration membrane 103 and the first electrode 51 in order to control the orientation. When the piezoelectric material of the piezoelectric membrane 52 is ScAlN, a lattice constant of the first electrode 51 made of Mo can be made close to ScAlN by using ScAlN also as an orientation control layer. As a result, the crystal orientation of the piezoelectric membrane 52 is uniform, and the piezoelectric characteristics can be improved.

[0033] FIG. 4 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the present embodiment, and is the cross-sectional view taken along the line C-C.

FIG. 5 is the front view schematically illustrating the internal structure of the liquid discharge head 1 according to the present embodiment, and is the cross-sectional view taken along the line A- A'.

FIG. 6 is the side view schematically illustrating the internal structure of the liquid discharge head 1 according to the present embodiment, and is the cross-sectional view taken along the line B-B'.

[0034]

As illustrated in FIGS. 5 and 6, the liquid discharge head 1 according to the present embodiment includes the nozzle plate 110, the pressure chamber substrate 100, the common liquid chamber substrate 120, the damper 130, and the frame 140 arranged in this order. [0035]

In the pressure chamber substrate 100, a region where the plurality of pressure chambers 4 is arranged is a pressure chamber array 40. The opening portion 4a of each pressure chamber 4 is opened on an upper surface (a surface on the common liquid chamber 3 side) of the pressure chamber array 40, and the common liquid chamber 3 formed in the common liquid chamber substrate 120 is arranged to face the opening portion 4a of each pressure chamber 4. In the present embodiment, as an example, a dimension of the pressure chamber 4 (a diameter of the opening portion 4a) is 220 micrometers (pm), and a width of a partition wall defining the pressure chamber 4 is 30 pm. As a result, a center-to-center distance L2 (see FIG. 6) between the opening portions 4a in the two adjacent pressure chambers 4 is 250 pm. [0036]

The damper 130 is disposed on the upper surface of the common liquid chamber substrate 120 (a surface opposite to the pressure chamber substrate 100). The common liquid chamber 3 communicates with a supply liquid storage chamber 31 formed in a frame 140 via a supply communication path 32 formed in the damper 130. As illustrated in FIG. 4, the supply communication path 32 of the present embodiment is branched into a plurality of (three in the illustrated example) sections by a partition wall 130a. The partition wall 130a mainly functions as a reinforcing member and is for securing a mechanical strength of the damper 130, and is for uniformly supplying liquid to the entire region of the common liquid chamber 3 (for uniformly supplying liquid to each pressure chamber 4). Therefore, as long as the mechanical strength of the damper 130 can be secured and the liquid can be supplied uniformly, the partition wall 130a (the reinforcing member) may not be provided and the supply communication path 32 may be configured by a single path.

[0037]

Liquid stored in an external liquid storage is supplied to the liquid discharge head 1 through a liquid supply port 33 of the frame 140. The liquid supplied from the liquid supply port 33 is supplied from the supply liquid storage chamber 31 to the common liquid chamber 3 through the supply communication path 32, and is supplied from the common liquid chamber 3 to each pressure chamber 4 through the opening portion 4a of each pressure chamber 4.

[0038]

In the present embodiment, as illustrated in FIGS. 5 and 6, the damper 130 includes a damper film 61 as a damper, a damper film holding member 62 that holds the damper film 61, and an air chamber 63 for securing displacement or vibration of the damper film 61. The air chamber 63 is opened to outside air through an atmosphere open hole 64.

[0039]

The damper film 61 is made of a highly flexible material, and is disposed at a position facing the opening portion 4a (in other words, the upper surface of the pressure chamber array 40) of each pressure chamber 4 via the common liquid chamber 3. In other words, the damper film 61 constitutes one wall portion (an upper wall surface) of the common liquid chamber 3. With such a configuration, in the damper 130, the damper film 61 is deformed according to a crosstalk pressure propagated to the liquid in the common liquid chamber 3, pressure fluctuation due to the crosstalk pressure generated in the common liquid chamber 3 can be reduced, and an effect of reducing the crosstalk (a fluid crosstalk) to be described later is exhibited.

[0040]

When the liquid in the pressure chamber 4 is pressurized by vibrating the vibration membrane 103 by the piezoelectric element 5 of the nozzle plate 110, the pressure becomes a force for discharging the liquid from the nozzle 2, but a part thereof escapes from the opening portion 4a of the pressure chamber 4 to the common liquid chamber 3 and becomes the crosstalk pressure. The crosstalk pressure that has escaped to the common liquid chamber 3 propagates the liquid in the common liquid chamber 3 and flows to another surrounding pressure chamber 4, causes fluctuation in the pressure of the liquid in the other pressure chambers 4, and affects the discharge of the liquid in the other pressure chambers 4 from the nozzle 2. [0041]

Here, in the present embodiment, since the common liquid chamber 3 is interposed between the damper film 61 and the opening portion 4a of each pressure chamber 4, it is necessary to dispose the damper film 61 away from the opening portion 4a of each pressure chamber 4 in order to secure the flow of liquid in the common liquid chamber 3. In other words, it is necessary to set a distance between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61, that is, the distance LI (see FIG. 6) between the upper surface of the pressure chamber array 40 and the damper film 61 to a size sufficient to secure a flow of the liquid in the common liquid chamber 3.

[0042]

At this time, if the distance LI between the upper surface of the pressure chamber array 40 and the damper film 61 is excessively increased in order to secure a sufficiently wide common liquid chamber 3, the crosstalk pressure absorbed by the damper film 61 decreases, and the crosstalk reduction effect decreases. Therefore, the crosstalk may occur. In particular, in the present embodiment, since a so-called nozzle vibration type is adopted, a liquid discharge head having a large number of nozzles (the number of pressure chambers) per unit area can be provided. However, in such a liquid discharge head, since the distance between the pressure chambers 4 is short, the crosstalk may occur. [0043]

Therefore, in the present embodiment, the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is equal to or less than the center-to-center distance L2 between the opening portions 4a of the two adjacent pressure chambers 4. With this configuration, most of the pressure wave (the crosstalk pressure) from the opening portion 4a of each pressure chamber 4 can reach the damper film 61 before reaching the opening portion 4a of another adjacent pressure chamber 4 through the liquid in the common liquid chamber 3. As a result, it is considered that the influence of the pressure wave (the crosstalk pressure) reaching the opening portion 4a of the other pressure chamber 4 from each pressure chamber 4 on the pressure fluctuation of the liquid in the other pressure chamber 4 can be reduced to be small, and a sufficient crosstalk reduction effect can be exhibited.

[0044]

However, when the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is too small, a fluid resistance (a viscous resistance or the like) of the liquid flowing through the common liquid chamber 3 becomes too high, and a problem that the liquid supply to each pressure chamber 4 becomes insufficient may occur. In particular, when a liquid having a high viscosity is used or when liquid discharge is performed at a high frequency, this problem becomes remarkable. In addition, if the minimum distance LI is too small, the common liquid chamber 3 becomes too narrow due to the deformation of the damper film 61 when the process of sucking out the liquid from the nozzle 2 side by a suction means is performed for a purpose of cleaning the nozzle 2. As a result, the flow of the liquid is hindered, and a sufficient cleaning effect cannot be obtained, or the damper film 61 comes into contact with the pressure chamber substrate 100 and is damaged.

[0045]

In consideration of such a problem, the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 in the liquid of the present embodiment is preferably 10 pm or more, and more preferably 50 pm or more.

[0046]

In addition, the damper film 61 is preferably a material having a low rigidity (a high flexibility), a durability, and a wettability to a liquid to be discharged. Specifically, as the damper film 61, a resin film such as polyimide (PI) or polyphenylene sulfide (PPS), or a metal membrane such as stainless steel or nickel is suitable. However, when the damper film 61 is too thin, a problem that pinholes are likely to happen occurs. Therefore, a thickness of the damper film 61 is preferably in a range of approximately 1 pm or more and 50 pm or less. [0047]

In a case where a resin film is used as the damper film 61, it is preferable to have a moisture permeation preventing membrane. This is to prevent a component of the liquid in the common liquid chamber 3 from entering the air chamber 63 via the damper film 61 and leaking from the atmosphere open hole 64 to outside air. The moisture permeation preventing membrane can be provided by, for example, film formation of depositing a metal or a metal oxide on a resin film by sputtering or the like.

[0048]

FIG. 7 is the graph illustrating the simulation result of the crosstalk reduction effect by the damper 130 in the present embodiment.

In this graph, the rate of change in a liquid discharge speed when the number of simultaneously driven nozzles (the number of adjacent nozzles) is changed is simulated for an example in which the damper 130 is not provided (an example without damper) and an example in which the damper 130 is provided (an example with damper). The rate of change in the liquid discharge speed is a rate of change when the liquid discharge speed during liquid discharging with merely one nozzle is 100%.

[0049]

In this simulation, the damper film 61 made of a stainless steel membrane having a thickness of 10 pm was used as the damper 130, and the minimum distance LI between the upper surface of a pressure chamber array 40 and the damper film 61 was set to 100 pm.

[0050]

As can be seen from the graph of FIG. 7, in a case of without damper, as the number of simultaneously driven nozzles is increased, for example, the liquid discharge speed when the number of simultaneously driven nozzles is 40 changes by 50% or more with respect to the liquid discharge speed when the number of simultaneously driven nozzles is 1. On the other hand, in a case of with damper, for example, even at the liquid discharge speed when the number of simultaneously driven nozzles is 40, the change rate is 5% or less with respect to the liquid discharge speed when the number of simultaneously driven nozzles is 1. By providing the damper 130 in this manner, the crosstalk reduction effect is exhibited.

[0051]

FIG. 8 is the graph illustrating the simulation result of the rate of change in the liquid discharge speed when the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is changed.

In this simulation, the number of simultaneously driven nozzles was 10. The rate of change in the liquid discharge speed in this simulation is the rate of change when the liquid discharge speed is 100% when the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is 100 pm.

[0052]

As can be seen from the graph of FIG. 8, when the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is 250 pm or less, the rate of change in the liquid discharge speed is reduced to 5% or less (within an allowable range). On the other hand, when the minimum distance LI is 500 pm, the rate of change in the liquid discharge speed is 20%.

[0053]

Here, a case where the number of simultaneously driven nozzles in the graph of FIG. 7 (a case where the minimum distance LI is 100 pm) is 10 is compared with a case where the minimum distance LI in the graph of FIG. 8 (a case where the number of simultaneously driven nozzles is 10) is 500 pm. According to this comparison, the rate of change in the liquid discharge speed when the minimum distance LI in the graph of FIG. 8 is 500 pm is substantially the same as that when the damper 130 is not provided (in a case where the damper is not provided in FIG. 7) although the damper 130 is provided. In other words, in a case where the minimum distance LI in the graph of FIG. 8 is 500 pm, it can be seen that the crosstalk reduction effect by the damper 130 is not obtained.

[0054]

On the other hand, from the graph of FIG. 8, when the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is 250 pm or less, the minimum distance LI is substantially equal to the minimum distance LI of 100 pm (the rate of change in the liquid discharge speed is 5% or less). Therefore, as in a case of with damper in the graph of FIG. 7 (the minimum distance LI is 100 pm), the change in the liquid discharge speed is reduced even when the number of simultaneous drive nozzles increases, and the sufficient crosstalk reduction effect is exhibited.

[0055]

A distance of 250 pm corresponds to the center-to-center distance L2 between the opening portions 4a in the two adjacent pressure chambers 4. This can be considered to be a result of a fact that most of the crosstalk pressure (the pressure wave) escaping from the opening portion 4a of each pressure chamber 4 to the common liquid chamber 3 during liquid discharging reaches the damper film 61 and is absorbed before reaching the opening portion 4a of another adjacent pressure chamber 4 through the liquid in the common liquid chamber 3 by satisfying LI < L2. In other words, if LI > L2, a component of the crosstalk pressure (the pressure wave) that is not absorbed by the damper film 61 and reaches the opening portion 4a of another adjacent pressure chamber 4 increases, the influence on the pressure fluctuation of the liquid in the other pressure chamber 4 cannot be ignored, and it is considered that the sufficient crosstalk reduction effect cannot be obtained.

[0056]

As described above, according to the present embodiment, since the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is equal to or less than the center-to-center distance L2 between the opening portions 4a of the two adjacent pressure chambers 4, the sufficient crosstalk reduction effect can be obtained.

[0057] First Modification

Next, a modification (hereinafter, this modification is referred to as a "first modification") of the liquid discharge head 1 according to the present embodiment will be described.

The liquid discharge head 1 of the first modification is different from the liquid discharge head 1 of the embodiment described above in that a position of the supply communication path 32 formed in the damper 130 is changed.

[0058]

FIG. 9 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the first modification, and is the cross-sectional view taken along the line C-C.

FIG. 10 is the side view schematically illustrating the internal structure of the liquid discharge head 1 according to the first modification, and is the cross-sectional view taken along the line B-B'.

[0059]

In the liquid discharge heads 1 of the embodiments described above, the supply communication path 32 for communicating the common liquid chamber 3 of the common liquid chamber substrate 120 and the supply liquid storage chamber 31 of the frame 140 is formed in an outer area from the pressure chamber array 40 in a transverse direction of the pressure chamber array 40 (an outer area from a long side 40a of the pressure chamber array 40 illustrated in FIG. 4). In other words, in the liquid discharge heads 1 of the embodiments described above, the supply communication path 32 for supplying liquid to the common liquid chamber 3 communicates with the common liquid chamber 3 outside the pressure chamber array 40 in the transverse direction of the pressure chamber array 40 including the plurality of pressure chambers 4.

[0060]

On the other hand, in the liquid discharge head 1 of the first modification, the supply communication path 32 is formed on the outer side in a longitudinal direction of the pressure chamber array 40 (the outer side of a short side 40b of the pressure chamber array 40). In other words, in the liquid discharge head 1 of the first modification, the supply communication path 32 for supplying liquid to the common liquid chamber 3 communicates with the common liquid chamber 3 outside in the longitudinal direction of the pressure chamber array 40 including the plurality of pressure chambers 4.

[0061]

According to the first modification, since the supply communication path 32 is formed on the outer side in the longitudinal direction of the pressure chamber array 40 (the outer side of the short side 40b of the pressure chamber array 40), it is not necessary to provide a space for forming the supply communication path 32 in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40. Accordingly, the downsizing of the liquid discharge head in the transverse direction of the pressure chamber array 40 can be achieved. In particular, in a case of using a head unit in which a plurality of liquid discharge heads is arranged side by side in the transverse direction of the pressure chamber array 40, there is a great advantage in downsizing the head unit by downsizing the liquid discharge head in the transverse direction of the pressure chamber array 40.

[0062]

However, in both the present embodiment and the present first modification, since the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is reduced in order to sufficiently obtain the crosstalk reduction effect, the fluid resistance (the viscous resistance or the like) of the liquid in the common liquid chamber 3 tends to be high. Therefore, when a distance in which the liquid flows in the common liquid chamber 3 is long (e.g., exceeds several [mm]), the fluid resistance becomes too high, and in the pressure chamber 4 far from the supply communication path 32, the liquid supply becomes insufficient, which may cause a problem that stable liquid discharge becomes difficult. In particular, this problem is remarkable in a case where ink viscosity is high or driving frequency is high.

[0063]

In the first modification, since the supply communication path 32 is formed on the outer side in the longitudinal direction of the pressure chamber array 40, the distance in which the liquid flows in the common liquid chamber 3 from the supply communication path 32 to the pressure chamber 4 far therefrom is longer than in a case of the embodiments described above in which the supply communication path 32 is formed in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40. Therefore, the embodiments described above are more advantageous in terms of the problems described above. In particular, the embodiments described above are more advantageous as a ratio between the long side 40a and the short side 40b of the pressure chamber array 40 is larger. [0064]

Of course, depending on conditions such as a case where the viscosity of the liquid to be used is low or a case where the driving frequency is low, the problem described above does not occur even in a configuration of the first modification, and the configuration of the first modification can be adopted.

[0065]

Second Modification

Next, another modification (hereinafter, this modification is referred to as a "second modification") of the liquid discharge head 1 according to the present embodiment will be described.

The liquid discharge head 1 of the second modification is different from the liquid discharge heads 1 of the embodiments described above in that a fluid resistance portion 4b is disposed in the opening portion 4a of each pressure chamber 4.

[0066] FIG. 11 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the second modification, and is the cross-sectional view taken along the line D-D'.

FIG. 12 is the side view schematically illustrating the internal structure of the liquid discharge head 1 in the second modification, and is the cross-sectional view taken along the line B-B'. [0067]

In the second modification, a fluid resistance substrate 150 is inserted between the pressure chamber substrate 100 and the common liquid chamber substrate 120. As illustrated in FIGS. 11 and 12, the fluid resistance substrate 150 is provided with the fluid resistance portion 4b in which an opening portion area (the opening portion area parallel to the nozzle surface) of the opening portion 4a is narrower than a cross-sectional area (the area of the cross section parallel to the nozzle surface) of the pressure chamber 4. By providing the fluid resistance portion 4b, the fluid resistance of the liquid moving from each pressure chamber 4 to the common liquid chamber 3 can be increased. [0068]

The fluid resistance substrate 150 may be one in which a plurality of opening portions narrower than the sectional area of the pressure chamber 4 (the area of the cross section parallel to the nozzle surface) is formed at positions corresponding to the pressure chambers 4. As the substrate of the fluid resistance substrate 150, for example, metal, silicon, ceramics, or resin can be used. The fluid resistance portion 4b (the opening portion formed in the fluid resistance substrate 150) can be formed by wet etching, dry etching, electro forming, cutting, laser processing, or the like. [0069]

By providing such a fluid resistance portion 4b, the crosstalk pressure generated in each pressure chamber 4 can be confined in each pressure chamber 4 as much as possible, and the crosstalk pressure leaking from each pressure chamber 4 to the common liquid chamber 3 through the opening portion 4a can be reduced. [0070]

According to the second modification, it is possible to provide the liquid discharge head 1 having a higher crosstalk reduction effect as compared with the embodiments described above in which the fluid resistance portion 4b is not provided. In particular, according to the second modification, since a margin of the crosstalk reduction effect is increased by providing the fluid resistance portion 4b, it is possible to increase the LI as much as possible within a condition of LI < L2 and reduce the fluid resistance of the liquid flowing through the common liquid chamber 3. In other words, according to the second modification, even when it is attempted to obtain the crosstalk reduction effect similar to that of the liquid discharge heads 1 of the embodiments described above, the fluid resistance of the liquid flowing through the common liquid chamber 3 can be reduced by increasing the LI, and a problem of unstable discharging performance due to insufficient liquid supply to the pressure chamber 4 hardly occurs. [0071]

Third Modification

Next, still another modification (hereinafter, this modification is referred to as a "third modification") of the liquid discharge head 1 according to the present embodiment will be described.

The third modification is an example of a head unit 10 in which the plurality of liquid discharge heads 1 is arranged side by side in the transverse direction of the pressure chamber array 40. The individual liquid discharge heads 1 of the head unit 10 are the same as those of the embodiments described above.

[0072]

FIG. 13 is the plan view schematically illustrating the internal structure of four liquid discharge heads 1 of the head unit 10 in the third modification, and is the cross-sectional view taken along the line C-C.

FIG. 14 is the side view schematically illustrating the internal structure of four liquid discharge heads 1 of the head unit 10 in the third modification, and is the cross-sectional view taken along the line A- A'.

[0073]

The head unit 10 of the third modification has a configuration in which four liquid discharge heads 1 of the embodiments described above are aligned and integrated in the transverse direction of the pressure chamber array 40. Such a head unit 10 can be used, for example, as a recording head (an inkjet head) of an image forming apparatus (a liquid discharge apparatus) that performs image formation using four types (Yellow (Y), magenta (M), cyan (C), black (K)) of different inks. By integrating the four liquid discharge heads 1 as in the third modification, a compact recording head can be obtained, and the number of assembling steps of the recording head and the image forming apparatus can be reduced.

[0074]

Fourth Modification

Next, still another modification (hereinafter, this modification is referred to as a "fourth modification") of the liquid discharge head 1 according to the present embodiment will be described.

The liquid discharge head 1 of the fourth modification is different from the liquid discharge heads 1 of the embodiments described above in including a supply flow path (the supply liquid storage chamber 31, the supply communication path 32, the liquid supply port 33, and the like) for supplying liquid to the common liquid chamber 3 and a delivery flow path for delivering liquid from the common liquid chamber 3.

[0075]

FIG. 15 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the fourth modification, and is the cross-sectional view taken along the line C-C'. FIG. 16 is the front view schematically illustrating the internal structure of the liquid discharge head 1 according to the fourth modification, and is the cross-sectional view taken along the line E-E'.

FIG. 17 is the side view schematically illustrating the internal structure of the liquid discharge head 1 according to the fourth modification, and is the cross-sectional view taken along the line F-F'.

[0076]

Also in the fourth modification, the liquid supplied from an external ink storage through the liquid supply port 33 of the frame 140 is supplied to the common liquid chamber 3 through the supply liquid storage chamber 31 and the supply communication path 32. However, in the fourth modification, the common liquid chamber 3 communicates with a delivery liquid storage chamber 35 formed in the frame 140 via the delivery communication path 34 formed in the damper 130. As a result, the liquid in the common liquid chamber 3 passes through the delivery liquid storage chamber 35 from the delivery communication path 34, and is returned to the external ink storage from a liquid delivery port 36 via an external pump or the like. In other words, the fourth modification is the liquid discharge head 1 of a liquid circulation system.

[0077]

According to the fourth modification, it is possible to circulate the liquid in the common liquid chamber 3. As a result, air bubbles present in the flow path in the liquid discharge head 1 such as the common liquid chamber 3 can be removed, or in a case of using a liquid having a component that is likely to settle, the component of the liquid can be reduced from settling in the flow path in the liquid discharge head 1 such as the common liquid chamber 3. [0078]

In particular, in the fourth modification, the supply communication path 32 and the delivery communication path 34 are formed in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40 (the outer area from the long side 40a of the pressure chamber array 40) with the pressure chamber array 40 interposed therebetween. Therefore, a distance in which the liquid flows in the common liquid chamber 3 facing the pressure chamber array 40 (a longest distance when the liquid flows from the supply communication path 32 to the delivery communication path 34) is minimized. Therefore, in the fourth modification, since the minimum distance LI between each opening portion 4a of the plurality of pressure chambers 4 and the damper film 61 is small, the fluid resistance (the viscous resistance or the like) of the liquid in the common liquid chamber 3 is high, but the fluid resistance of the liquid in the common liquid chamber 3 can be reduced to be low by minimizing the distance in which the liquid flows in the common liquid chamber 3. [0079]

Fifth Modification Next, still another modification (hereinafter, this modification is referred to as a "fifth modification") of the liquid discharge head 1 according to the present embodiment will be described.

The fifth modification is an example of the head unit 10 in which the plurality of the liquid discharge heads 1 of the fourth modification described above is arranged side by side in the transverse direction of the pressure chamber array 40.

[0080]

FIG. 18 is the plan view schematically illustrating the internal structure of four liquid discharge heads 1 of the head unit 10 in the present fifth modification, and is the cross- sectional view taken along the line C-C.

FIG. 19 is the side view schematically illustrating the internal structure of the four liquid discharge heads 1 of the head unit 10 in the present fifth modification, and is the cross- sectional view taken along the line E-E'.

[0081]

The head unit 10 of the present fifth modification has a configuration in which four liquid discharge heads 1 (liquid circulation type liquid discharge heads) of the fourth modification described above are arranged and integrated in the transverse direction of the pressure chamber array 40. The head unit 10 can be used as, for example, the recording head (the inkjet head) of the image forming apparatus (the liquid ejecting apparatus) that forms an image using four types (Yellow (Y), magenta (M), cyan (C), black (K)) of different inks, similarly to the head unit 10 of the third modification described above. By integrating the four liquid discharge heads 1 as in the fifth modification, the compact recording head can be obtained, and the number of assembling steps of the recording head and the image forming apparatus can be reduced.

[0082]

Sixth Modification

Next, still another modification (hereinafter, this modification is referred to as a "sixth modification") of the liquid discharge head 1 according to the present embodiment will be described.

The liquid discharge head 1 of the sixth modification is different from the liquid discharge heads 1 of the embodiments described above in that the liquid circulation system including a supply flow path (the supply liquid storage chamber 31, the supply communication path 32, the liquid supply port 33, and the like) for supplying liquid to the common liquid chamber 3 and a delivery flow path for delivering liquid from the common liquid chamber 3, similarly to the fourth modification described above. However, the liquid discharge head 1 of the sixth modification is different from the liquid discharge head 1 of the fourth modification described above in that the position of the delivery communication path 34 formed in the damper 130 is changed.

[0083] FIG. 20 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the sixth modification, and is the cross-sectional view taken along the line C-C.

FIG. 21 is the front view schematically illustrating the internal structure of the liquid discharge head 1 according to the sixth modification, and is the cross-sectional view taken along the line G-G'.

[0084]

In the liquid discharge head 1 of fourth modification described above, both the supply communication path 32 and the delivery communication path 34 are formed in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40 (the outer area from the long side 40a of the pressure chamber array 40). Therefore, it is necessary to provide a space for forming both the supply communication path 32 and the delivery communication path 34 outside the pressure chamber array 40 in the transverse direction, and the liquid discharge head is likely to increase in size in the transverse direction of the pressure chamber array 40. In particular, in a case where the plurality of liquid discharge heads 1 is arranged side by side in the transverse direction of the pressure chamber array 40 as in the head unit 10 of the fifth modification illustrated in FIGS. 18 and 19, the head unit 10 is significantly increased in size in the transverse direction of the pressure chamber array 40.

[0085]

In addition, since a space for forming both the supply communication path 32 and the delivery communication path 34 is disposed outside the pressure chamber array 40 in the transverse direction, the pressure chamber substrate 100 increases in size in the transverse direction of the pressure chamber array 40. In this case, the area of the pressure chamber substrate 100 increases. For the pressure chamber substrate 100 manufactured using a microelectromechanical systems (MEMS) process, an increase in the substrate area directly leads to an increase in costs.

[0086]

On the other hand, in the liquid discharge head 1 of the sixth modification, the supply communication path 32 is formed in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40, but the delivery communication path 34 is formed on the outer side in the longitudinal direction of the pressure chamber array 40 (on the outer side of the short side 40b of the pressure chamber array 40). According to this, since a space for forming the delivery communication path 34 can be omitted outside the pressure chamber array 40 in the transverse direction, the liquid discharge head can be downsized in the transverse direction of the pressure chamber array 40 as compared with the liquid discharge head 1 of Modification 4 described above. This downsizing effect is, in particular, effective in a case where the plurality of the liquid discharge heads 1 of the sixth modification is arranged side by side in the transverse direction of the pressure chamber array 40 as in the head unit 10 illustrated in FIG. 22. [0087]

Further, in the liquid discharge head 1 of the sixth modification, by forming the delivery communication path 34 on the outer side in the longitudinal direction of the pressure chamber array 40, the substrate area which has to form the delivery communication path 34 can be reduced as compared with the liquid discharge head 1 of the fourth modification in which the delivery communication path 34 is formed in the outer area from the pressure chamber array 40 in the transverse direction of the pressure chamber array 40. Therefore, the substrate area of the pressure chamber substrate 100 can be made smaller than that of the liquid discharge head 1 of Modification 4 described above, and an increase in cost can be reduced. [0088]

In the liquid discharge head 1 of sixth modification, since the delivery communication path 34 is formed outside the pressure chamber array 40 in the longitudinal direction, a distance (the longest distance when the liquid flows from the supply communication path 32 to the delivery communication path 34) in which the liquid flows in the common liquid chamber 3 while facing the pressure chamber array 40 is longer than that of the liquid discharge head 1 of the fourth modification in which both the supply communication path 32 and the delivery communication path 34 are formed outside the pressure chamber array 40 in the short direction. Therefore, when the liquid is discharged while circulating the liquid in the common liquid chamber 3, the pressure chamber 4 in which the liquid supply is insufficient is generated, and there may be a problem that it is difficult to stably discharge the liquid. In particular, this problem is remarkable in a case where ink viscosity is high or driving frequency is high.

[0089]

In a case where such a failure may occur, merely during initial filling of the liquid discharge head 1 with the liquid or during maintenance of the liquid discharge head 1, the liquid may be delivered from the common liquid chamber 3 using the delivery flow path (e.g., the delivery communication path 34, the delivery liquid storage chamber 35, and the liquid delivery port 36), and air bubbles may be delivered. In this case, since the liquid in the common liquid chamber 3 is not circulated during operation of performing liquid discharge, the pressure chamber 4 in which liquid supply is insufficient is less likely to occur, and stable liquid discharge becomes relatively easy.

[0090]

Note that the present sixth modification may have a configuration in which the supply flow path and the delivery flow path are interchanged. In other words, the supply communication path 32 may be formed outside the pressure chamber array 40 in the longitudinal direction, and the delivery communication path 34 may be formed outside the pressure chamber array 40 in the transverse direction.

[0091]

Seventh Modification Next, still another modification (hereinafter, this modification is referred to as a "seventh modification") of the liquid discharge head 1 according to the present embodiment will be described.

The liquid discharge head 1 of the seventh modification is different from the liquid discharge heads 1 of the embodiments described above in that the liquid circulation system including a supply flow path (the supply liquid storage chamber 31, the supply communication path 32, the liquid supply port 33, and the like) for supplying liquid to the common liquid chamber 3 and a delivery flow path (e.g., the delivery communication path 34, the delivery liquid storage chamber 35, and the liquid delivery port 36) for delivering liquid from the common liquid chamber 3, similarly to the fourth modification and the sixth modification described above. However, in the liquid discharge head 1 of the seventh modification, positions of the supply communication path 32 and the delivery communication path 34 formed in the damper 130 are different from those of the liquid discharge heads 1 of the fourth modification and the sixth modification described above.

[0092]

FIG. 23 is the plan view schematically illustrating the internal structure of the liquid discharge head 1 according to the seventh modification, and is a cross-sectional view taken along the line C-C.

FIG. 24 is the front view schematically illustrating the internal structure of the liquid discharge head 1 according to the seventh modification, and is the cross-sectional view taken along the line H-H'.

[0093]

In the liquid discharge head 1 of the seventh modification, both the supply communication path 32 and the delivery communication path 34 are formed on the outer side in the longitudinal direction of the pressure chamber array 40 (the outer side of the short side 40b of the pressure chamber array 40). According to this, since the space for forming the supply communication path 32 and the space for forming the delivery communication path 34 can be omitted outside the pressure chamber array 40 in the transverse direction, the liquid discharge head can be downsized in the transverse direction of the pressure chamber array 40 as compared with the liquid discharge heads 1 of the fourth modification and the sixth modification described above. This downsizing effect is, in particular, effective in a case where a plurality of the liquid discharge heads 1 of the seventh modification is arranged side by side in the transverse direction of the pressure chamber array 40 as in the head unit 10 illustrated in FIG. 25.

[0094]

In the liquid discharge head 1 of the seventh modification, since both the supply communication path 32 and the delivery communication path 34 are formed outside the pressure chamber array 40 in the longitudinal direction, the substrate area of the pressure chamber substrate 100 can be made smaller than that of the liquid discharge head 1 of the fourth modification and further than that of the liquid discharge head 1 of the sixth modification, and the cost increase can be further reduced. The liquid discharge head 1 of the seventh modification also has an advantage in that the configurations of the supply flow path and the delivery flow path can be easily simplified.

[0095]

In the liquid discharge head 1 of the seventh modification, since both the supply communication path 32 and the delivery communication path 34 are formed outside the pressure chamber array 40 in the longitudinal direction, a distance in which the liquid flows in the common liquid chamber 3 while facing the pressure chamber array 40 (the longest distance when the liquid flows from the supply communication path 32 to the delivery communication path 34) is longer than that of the liquid discharge head 1 of the fourth modification. Therefore, the pressure chamber 4 in which the liquid supply is insufficient is generated, and a problem that it is difficult to stably discharge the liquid may occur. In particular, this problem is remarkable in a case where ink viscosity is high or driving frequency is high.

[0096]

However, in the liquid discharge head 1 of the seventh modification, since both the supply communication path 32 and the delivery communication path 34 are formed outside the pressure chamber array 40 in the longitudinal direction, the substrate area of the pressure chamber substrate 100 can be reduced, and the cost increase can be further reduced. Depending on conditions such as a case where the viscosity of the liquid to be used is low and a case where the driving frequency is low, the problem described above does not occur even in the configuration of the seventh modification, and the configuration of the seventh modification can be adopted. Note that the delivery communication path 34 may be used as a second supply communication path, and liquid may be supplied from both the supply communication path 32 and the delivery communication path 34.

[0097]

Next, a liquid discharge apparatus according to an embodiment of the present disclosure will be described with reference to FIGS. 26 and 27.

FIG. 26 is the schematic explanatory view of the printing apparatus that is the inkjet recording device that is the image forming device as the liquid discharge apparatus in the present embodiment.

FIG. 27 is the plan explanatory view of the example of the head unit of the printing apparatus of the present embodiment.

[0098]

A printing apparatus 500, which is an apparatus that discharges liquid, includes a carry-in unit 501 that carries in a continuous body 510, and a guide conveyance unit 503 that guides and conveys the continuous body 510 carried in from the carry-in unit 501 to a printing means 505. The printing apparatus 500 also includes the printing means 505 that performs printing for discharging liquid onto the continuous body 510 to form an image, a drying means 507 that dries the continuous body 510, and a carry-out unit 509 that carries out the continuous body 510.

[0099]

The continuous body 510 is fed from a winding roller 511 of the carry-in unit 501, guided and conveyed with rollers of the carry-in unit 501, the guide conveyance unit 503, the drying means 507, and the carry-out unit 509, and wound around a take-up roller 591 of the carry-out unit 509. In the printing means 505, the continuous body 510 is conveyed opposite to a head unit 550 on a conveyance guide member 559. The head unit 550 discharges liquid to form an image on the continuous body 510.

[0100]

In the printing apparatus 500 of the present embodiment, the head unit 550 includes two head modules 100A and 100B according to the present embodiments described above in a common base member 552.

[0101]

When an arrangement direction of the liquid discharge heads 1 in a direction orthogonal to a conveyance direction of the liquid discharge head modules 100A and 100B is defined as a head arrangement direction, liquid of the same color is discharged in head rows 1A1 and 1A2 of the liquid discharge head module 100A. Similarly, head rows 1B1 and 1B2 of the liquid discharge head module 100A are grouped as one set that discharges liquid of the same desired color. Head rows 1C1 and 1C2 of the liquid discharge head module 100B are grouped as one set that discharges liquid of the same desired color. Head rows 1D1 and 1D2 of the liquid discharge head module 100B are grouped as one set to discharge liquid of the same desired color.

[0102]

Next, a printing apparatus as a liquid discharge apparatus according to another embodiment of the present disclosure will be described with reference to FIGS. 28 and 29.

FIG. 28 is the explanatory plan view of the main part of the printing apparatus according to the present embodiment.

FIG. 29 is the explanatory side view of the main part of the printing apparatus according to the present embodiment.

[0103]

The printing apparatus 500 of the present example is a serial type device, and a carriage 403 reciprocates in a main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged between a left side plate 491 A and a right side plate 49 IB to moveably hold the carriage 403. The main scanning motor 405 reciprocally moves the carriage 403 in a main scanning direction via the timing belt 408 bridged between a drive pulley 406 and a driven pulley 407.

[0104] A liquid discharge unit 440 in which the liquid discharge head 1 and the head tank 441 according to an embodiment of the present disclosure are integrated is mounted on the carriage 403. The liquid discharge head 1 discharges liquid of each color of, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head 1 includes a nozzle row including multiple nozzles arrayed in a sub-scanning direction that is orthogonal to the main scanning direction. The liquid discharge head 1 is mounted so that ink droplets are discharged downward. The liquid discharge head 1 is coupled to a liquid circulation device, and a liquid of a demanded color is circulated and supplied.

[0105]

The printing apparatus 500 includes a conveyor 495 to convey a sheet 410. The conveyor 495 includes a conveyance belt 412 as a conveyor and a sub scan motor 416 to drive the conveyance belt 412. The conveyance belt 412 attracts and conveys the sheet 410 to a position facing the liquid discharge head 1. The conveyance belt 412 is an endless belt stretched between a conveyance roller 413 and a tension roller 414. Attraction may be applied by electrostatic adsorption, air suction, or the like. The conveyance belt 412 rotates in the sub-scanning direction as the conveyance roller 413 is rotationally driven by the sub scan motor 416 via the timing belt 417 and the timing pulley 418.

[0106]

At one side in the main scanning direction of the carriage 403, a maintenance and recovery mechanism 420 to maintain the liquid discharge head 1 in good condition is disposed on a transverse side of the conveyance belt 412. The maintenance and recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface of the liquid discharge head 1, a wiper member 422 for wiping the nozzle surface, and the like. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the conveyor 495 are mounted onto a housing including the side plates 491 A and 49 IB and a back plate 491C.

[0107]

In the printing apparatus 500 configured as described above, the sheet 410 is fed and attracted onto the conveyance belt 412, and the sheet 410 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 412. The liquid discharge head 1 is driven in response to image signals while the carriage 403 moves in the main scanning direction, to discharge liquid to the sheet 410 stopped, thus forming an image on the sheet 410. [0108]

Next, a liquid discharge unit according to another embodiment of the present disclosure will be described with reference to FIG. 30.

FIG. 30 is the explanatory plan view of the main part of the liquid discharge unit according to the present embodiment.

[0109] The liquid discharge unit 440 includes a housing portion including side plates 491 A and 49 IB and a back plate 491C, the main scanning movement mechanism 493, the carriage 403, and the liquid discharge head 1 among members of the liquid discharge apparatus.

[0110]

Note that, in the liquid discharge unit 440, the maintenance and recovery mechanism 420 described above may be mounted on the side plate 49 IB, for example.

[0111]

Next, a liquid discharge unit according to still another embodiment of the present disclosure will be described with reference to FIG. 31.

FIG. 31 is the explanatory front view of the liquid discharge unit according to the present embodiment.

[0112]

The liquid discharge unit 440 includes the liquid discharge head 1 to which a channel component 444 is attached, and a tube 456 coupled to the channel component 444. [0113]

The channel component 444 is disposed inside a cover 442. Instead of the channel component 444, the liquid discharge unit 440 may include the head tank 441. A connector 443 electrically connected with the liquid discharge head 1 is disposed on an upper part of the channel component 444.

[0114]

In the present embodiment, discharged liquid is not limited to a particular liquid as long as the liquid has a viscosity or surface tension to be discharged from a head (a liquid discharge head). However, preferably, the viscosity of the liquid is not greater than 30 mPa-s under ordinary temperature and ordinary pressure or by heating or cooling. 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 deoxyribonucleic acid (DNA), amino acid, protein, or calcium, or an edible material such as a natural colorant. These can be used in, for example, inkjet ink, 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.

[0115]

The "liquid discharge unit" is a set of components relating to liquid discharge, and represents integrating the liquid discharge head with functional components or mechanisms. For example, the "liquid discharge unit" includes a combination of the liquid discharge head with at least one of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0116]

Examples of the integration include a combination in which the liquid discharge head and one or more functional components and mechanisms are secured to each other through, for example, fastening, bonding, or engaging, and a combination in which one of the liquid discharge head and the functional components and mechanisms is movably held by another. The liquid discharge head may be detachably attached to the functional components and mechanisms.

[0117]

For example, the liquid discharge head and the head tank may form the liquid discharge unit as an integration. Alternatively, the liquid discharge head and the head tank connected with a tube or the like may form the liquid discharge unit as an integration. A unit including a filter may be added at a position between the head tank and the liquid discharge head of the liquid discharge unit.

[0118]

In another example, the liquid discharge head and the carriage may form the liquid discharge unit as an integration.

[0119]

The liquid discharge unit includes the liquid discharge head movably held by a guide member that forms part of a main scanning movement mechanism, so that the liquid discharge head and the main scanning movement mechanism form an integration. The liquid discharge unit may include the liquid discharge head, the carriage, and the main scanning movement mechanism that form an integration.

[0120]

A cap that forms a part of the maintenance and recovery mechanism may be secured to the carriage mounting the liquid discharge head so that the liquid discharge head, the carriage, and the maintenance and recovery mechanism form an integration to form the liquid discharge unit.

[0121]

The liquid discharge unit includes the tube coupled to the head tank or the liquid discharge head mounting a channel component so that the liquid discharge head and the supply mechanism form an integration. A liquid in a liquid reservoir source is supplied to the liquid discharge head through this tube.

[0122]

The main scanning movement mechanism may be a guide member merely. The supply mechanism may be a tube merely or a filler merely.

[0123]

Here, the "liquid discharge unit" is described in a combined manner with the liquid discharge head, but it includes integrating a head module including the liquid discharge head described above or a head unit with the functional components and mechanisms described above.

[0124]

The term "liquid discharge apparatus" also includes the liquid discharge head, the liquid discharge unit, the head module, the head unit, and the like, as well as an apparatus that discharges liquid by driving the liquid discharge head. The liquid discharge apparatus may not just be an apparatus that discharges liquid to a material onto which liquid can adhere, but also be an apparatus to discharge liquid toward gas or into liquid.

[0125]

The liquid discharge apparatus may include a pretreatment device, a post-treatment device, and the like, in addition to means related to feeding, carrying, sheet ejection onto which liquid can adhere.

[0126]

The "liquid discharge apparatus" may be, for example, the image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge a fabrication liquid to a powder layer in which a powder material is formed in layers to form a three-dimensional fabrication object.

[0127]

The "liquid discharge apparatus" is not limited to an apparatus to discharge liquid to visualize meaningful images, such as letters or figures. For example, the liquid discharge apparatus may be an apparatus to form meaningless images, such as meaningless patterns, or fabricate three-dimensional images.

[0128]

The term "a material onto which liquid can adhere" described above represents a material on which the liquid is at least temporarily adhered, a material on which the liquid is adhered and fixed, or a material into which the liquid is adhered to permeate. Examples of the "material on which liquid can adhere" include recording media such as paper sheet, recording paper, recording sheet of paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, and media such as powder layers, organ models, and testing cells. The "material on which liquid can adhere" includes any material on which liquid can adhere, unless particularly limited.

[0129]

Examples of the "material onto which liquid can adhere" include any materials on which liquid can adhere even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramic.

[0130]

The "liquid discharge apparatus" may be an apparatus to relatively move the liquid discharge head and the material on which liquid can adhere. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial type apparatus that moves the liquid discharge head or a line type apparatus that does not move the liquid discharge head.

[0131]

In addition, another example of the "liquid discharge apparatus" is a treatment liquid application apparatus that discharges a treatment liquid onto a sheet in order to apply the treatment liquid to the surface of the sheet for a purpose of modifying the surface of the sheet. In addition, there is also an injection granulation apparatus that injects a composition liquid in which a raw material is dispersed in a solution through a nozzle to granulate fine particles of the raw material.

[0132]

The terms of image formation, recording, printing, image printing, and fabricating used in the present application may be used synonymously with each other.

[0133]

The embodiments described above are limited examples, and the present disclosure includes, for example, the following aspects having advantageous effects.

First aspect

A liquid discharge head (e.g., the liquid discharge head 1) includes: a plurality of nozzles (e.g., the nozzles 2) that discharge liquid; a plurality of pressure chambers (e.g., the pressure chambers 4), each of which communicates with a corresponding one of the plurality of nozzles; a plurality of actuators (e.g., the piezoelectric elements 5), each of which is disposed on a nozzle communication wall (e.g., the nozzle plate 110) of a corresponding one of the plurality of pressure chambers to pressurize liquid in the corresponding one of the plurality of pressure chambers; a common liquid chamber (e.g., the common liquid chamber 3) that communicates with the plurality of pressure chambers; and a damper (e.g., the damper film 61) is disposed at a position facing opening portions of the plurality of pressure chambers, the opening portions facing the common liquid chamber. A minimum distance (e.g., the minimum distance LI) between the damper and each of the opening portions is equal to or less than a center-to-center distance (e.g., the center-to-center distance L2) between adjacent two of the opening portions of the plurality of pressure chambers.

In a configuration in which the damper is disposed so as to form a wall portion of a flow path from the common liquid chamber to each pressure chamber as in a liquid discharge head, the arrangement space of the damper is provided, and thus it is difficult to shorten the distance between the adjacent pressure chambers. Therefore, an inter-nozzle distance is not shortened, and the number of nozzles per unit area is not increased.

In the present aspect, the common liquid chamber is disposed so as to face and communicate with the respective opening portions of the plurality of pressure chambers, and the damper is disposed so as to face the respective opening portions of the plurality of pressure chambers via the common liquid chamber. According to this, since it is not necessary to arrange the damper so as to form the wall portion of the flow path from the common liquid chamber to each pressure chamber, the distance between the adjacent pressure chambers can be shortened as compared with the above-described configuration, and the number of nozzles per unit area can be increased by shortening the inter-nozzle distance.

However, in this configuration, depending on a setting of a height of the common liquid chamber interposed between the damper and each opening portion of the plurality of pressure chambers (the distance between the damper and each opening portion of the plurality of pressure chambers), it has been confirmed that crosstalk happens in which a pressure wave of liquid generated in each pressure chamber by actuator driving propagates to another pressure chamber.

Therefore, in the present aspect, the minimum distance between each opening portion of the plurality of pressure chambers and the damper is equal to or less than the center-to-center distance between the opening portions of the two adjacent pressure chambers. With this configuration, most of the pressure wave from the opening portion of each pressure chamber can reach the damper before flowing through the liquid in the common liquid chamber to the opening portion of another adjacent pressure chamber. As a result, the influence of the pressure wave reaching the opening portion of another pressure chamber from each pressure chamber on the pressure fluctuation of the liquid in the other pressure chamber can be reduced to be small, and the crosstalk can be reduced.

[0134]

Second aspect

In the first aspect, the minimum distance (e.g., the minimum distance LI) is 250 pm or less. According to this, the number of nozzles per unit area can be increased, and the crosstalk can be reduced.

[0135]

Third aspect

In the first or second aspect, the minimum distance (e.g., the minimum distance LI) is 10 pm or more.

According to this, it is easy to secure the flow of the liquid in the common liquid chamber, reduce the generation of the pressure chamber in which the liquid supply is insufficient, and achieve a stable liquid discharge.

[0136]

Fourth aspect

In any one of the first to third aspects, a supply flow path (e.g., the supply liquid storage chamber 31, a supply communication path 32, and a liquid supply port 33) that supplies liquid to the common liquid chamber is provided, and the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array (e.g., the pressure chamber array 40) including the plurality of pressure chambers.

Accordingly, even if a fluid resistance of the liquid in the common liquid chamber (e.g., the common liquid chamber 3) increases by reducing the minimum distance (e.g., the minimum distance LI) between the opening portion of each pressure chamber and the damper, the fluid resistance of the liquid in the common liquid chamber (e.g., the common liquid chamber 3) can be reduced from increasing by reducing the distance by which the liquid supplied from the supply flow path flows to each pressure chamber through the common liquid chamber. Therefore, it is possible to reduce the occurrence of the pressure chamber in which liquid supply is insufficient and to achieve the stable liquid discharge.

[0137]

Fifth aspect In any one of the first to third aspects, a supply flow path (e.g., the supply liquid storage chamber 31, the supply communication path 32, and the liquid supply port 33) that supplies liquid to the common liquid chamber and a delivery flow path (e.g., the delivery communication path 34, the delivery liquid storage chamber 35, and the liquid delivery port 36) that discharges liquid from the common liquid chamber are provided.

Accordingly, since the liquid in the common liquid chamber can be circulated, air bubbles present in the flow path in the liquid discharge head such as the common liquid chamber can be removed, or in a case of using a liquid having a component that is likely to settle, components of the liquid can be reduced from settling in the flow path in the liquid discharge head such as the common liquid chamber.

[0138]

Sixth aspect

In the fifth aspect, the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array (e.g., the pressure chamber array 40) including the plurality of pressure chambers, and the delivery flow path communicates with the common liquid chamber outside in the longitudinal direction of the pressure chamber array.

Accordingly, the downsizing in the transverse direction can be achieved as compared with a configuration in which both the supply flow path and the delivery flow path communicate with the common liquid chamber outside the pressure chamber array in the transverse direction. As compared with the configuration in which both the supply flow path and the delivery flow path communicate with the common liquid chamber outside the pressure chamber array in the longitudinal direction, the liquid flows in a longer distance in the common liquid chamber, the fluid resistance of the liquid in the common liquid chamber (e.g., the common liquid chamber 3) increases, and circulation in the common liquid chamber becomes difficult in some cases. However, since the delivery flow path can be used as a liquid discharge path during initial filling or maintenance of the liquid, the bubbles are easily discharged, and the stable liquid discharge becomes relatively easy.

[0139]

Seventh aspect

In the fifth aspect, the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array including the plurality of pressure chambers, and the delivery flow path communicates with the common liquid chamber outside in the transverse direction of the pressure chamber array.

According to this, as compared with the configuration in which the supply flow path communicates with the common liquid chamber outside in the transverse direction of the pressure chamber array and the delivery flow path communicates with the common liquid chamber outside in the longitudinal direction of the pressure chamber array, the distance in which the liquid discharged from the common liquid chamber flows to the delivery flow path is shortened, the fluid resistance of the liquid in the common liquid chamber (e.g., the common liquid chamber 3) is reduced to be low, the occurrence of the pressure chamber in which the liquid supply is insufficient is reduced, the stable liquid discharge can be achieved, and the liquid in the common liquid chamber (e.g., the common liquid chamber 3) can be circulated. As a result, the air bubbles present in the flow path in the liquid discharge head (e.g., the liquid discharge head 1) such as the common liquid chamber (e.g., the common liquid chamber 3) can be removed, or in a case of using liquid having a component that is likely to settle, it is possible to reduce the liquid component from settling in the flow path in the liquid discharge head (e.g., the liquid discharge head 1) such as the common liquid chamber (e.g., the common liquid chamber 3).

[0140]

Eighth aspect

In any one of the first to seventh aspects, the opening portion is provided with a fluid resistance portion (e.g., the fluid resistance portion 4b).

Accordingly, the fluid resistance portion can close the crosstalk pressure generated in each pressure chamber as much as possible in each pressure chamber, and can reduce the crosstalk pressure leaking from each pressure chamber to the common liquid chamber through the opening portion. In particular, according to the present aspect, since a margin of the crosstalk reduction effect is increased by providing the fluid resistance portion, the minimum distance (e.g., the minimum distance LI) between the opening portion (e.g., the opening portion 4a) and the damper can be made as large as possible to reduce the fluid resistance of the liquid flowing through the common liquid chamber. In other words, according to the present aspect, even in a case where it is attempted to obtain a crosstalk reduction effect similar to that of the liquid discharge head in which such a fluid resistance portion is not provided, the minimum distance (e.g., the minimum distance LI) between the opening portion (e.g., the opening portion 4a) and the damper can be made larger to reduce the fluid resistance of the liquid flowing through the common liquid chamber, and a problem of unstable discharging performance due to insufficient liquid supply to the pressure chamber hardly occurs.

[0141]

Ninth aspect

A liquid discharge apparatus includes the liquid discharge head according to any one of the first to eighth aspects.

According to this, it is possible to provide a liquid discharge apparatus that increases the number of nozzles per unit area and reducing the crosstalk. 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. [0142] This patent application is based on and claims priority to Japanese Patent Application No. 2023-003283, filed on January 12, 2023, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

[Reference Signs List]

[0143]

1 Liquid discharge head

2 Nozzle

3 Common liquid chamber

4 Pressure chamber

4a Opening portion

4b Fluid resistance portion

5 Piezoelectric element

10 Head unit

31 Supply liquid storage chamber

32 Supply communication path

33 Liquid supply port

34 Delivery communication path

35 Delivery liquid storage chamber

36 Liquid delivery port

40 Pressure chamber array

40a Long side

40b Short side

51 First electrode

52 Piezoelectric membrane

53 Second electrode

61 Damper film

62 Damper film holding member

63 Air chamber

64 Atmosphere open hole

100 Pressure chamber substrate

101 Drive circuit

102 Wiring portion

103 Vibration membrane

110 Nozzle plate

111 Nozzle forming portion

112 Liquid-repellent membrane

120 Common liquid chamber substrate

130 Damper

130a Partition wall

140 Frame

Claims

[CLAIMS]

[Claim 1]

A liquid discharge head, comprising: a plurality of nozzles to discharge liquid; a plurality of pressure chambers, each of which communicates with a corresponding one of the plurality of nozzles; a plurality of actuators, each of which is disposed on a nozzle communication wall of a corresponding one of the plurality of pressure chambers to pressurize liquid in the corresponding one of the plurality of pressure chambers; a common liquid chamber that communicates with the plurality of pressure chambers; and a damper disposed at a position facing opening portions of the plurality of pressure chambers, the opening portions facing the common liquid chamber, a minimum distance between the damper and each of the opening portions being equal to or less than a center-to-center distance between adjacent two of the opening portions.

[Claim 2]

The liquid discharge head according to claim 1, wherein the minimum distance is 250 micrometers or less.

[Claim 3]

The liquid discharge head according to claim 1 or 2, wherein the minimum distance is 10 micrometers or more.

[Claim 4]

The liquid discharge head according to any one of claims 1 to 3, further comprising a supply flow path to supply liquid to the common liquid chamber, wherein the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array including the plurality of pressure chambers.

[Claim 5]

The liquid discharge head according to any one of claims 1 to 3, further comprising: a supply flow path to supply liquid to the common liquid chamber; and a delivery flow path to deliver liquid from the common liquid chamber.

[Claim 6]

The liquid discharge head according to claim 5, wherein the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array including the plurality of pressure chambers, and the delivery flow path communicates with the common liquid chamber outside in a longitudinal direction of the pressure chamber array.

[Claim 7]

The liquid discharge head according to claim 5, wherein the supply flow path communicates with the common liquid chamber outside in a transverse direction of a pressure chamber array including the plurality of pressure chambers, and the delivery flow path communicates with the common liquid chamber outside in the transverse direction of the pressure chamber array.

[Claim 8]

The liquid discharge head according to any one of claims 1 to 7, wherein a fluid resistance portion is disposed at each of the opening portions.

[Claim 9]

A liquid discharge apparatus, comprising the liquid discharge head according to any one of claims 1 to 9.