CN114248548A

CN114248548A - Liquid spray head

Info

Publication number: CN114248548A
Application number: CN202110796120.7A
Authority: CN
Inventors: 关雅志
Original assignee: Toshiba TEC Corp
Current assignee: Toshiba TEC Corp
Priority date: 2020-09-24
Filing date: 2021-07-14
Publication date: 2022-03-29
Also published as: JP2022052930A; EP3974190A1

Abstract

The invention provides a liquid ejecting head which is easy to manufacture. A liquid ejecting head according to an embodiment includes: a nozzle plate formed with nozzles; an actuator disposed opposite to the nozzle plate and having a groove constituting a plurality of pressure chambers communicating with the nozzles; a liquid repellent film formed on a predetermined first region of a surface of the actuator; and an electrode layer formed in a second region different from the first region in the surface of the actuator.

Description

Liquid spray head

Technical Field

Embodiments of the present invention relate to a liquid ejection head.

Background

In an ink jet head that discharges ink droplets from nozzles provided in a nozzle plate by pressurizing ink with a piezoelectric member, electrodes are formed on the piezoelectric member in order to apply a voltage to the piezoelectric member. The electrode is formed by a liquid phase film forming method such as a plating method, and then patterned so as to be formed on the entire surface inside the pressure chamber. Ink is supplied from a common ink chamber to the pressure chambers.

Patent document 1: japanese patent laid-open publication No. 2019-51636

Disclosure of Invention

Technical problem to be solved by the invention

The present invention is directed to provide a liquid ejecting head which is easy to manufacture.

Means for solving the technical problem

A liquid ejecting head according to an embodiment includes: a nozzle plate formed with nozzles; an actuator disposed opposite to the nozzle plate and having a groove that constitutes a plurality of pressure chambers communicating with the nozzles; a liquid repellent film formed on a predetermined first region of a surface of the actuator; and an electrode layer formed in a second region different from the first region in the surface of the actuator.

Drawings

Fig. 1 is a perspective view showing an ink jet head according to an embodiment.

Fig. 2 is a boundary perspective view showing a partial structure of the inkjet head according to the embodiment.

Fig. 3 is a sectional view showing a partial structure of the ink jet head in an enlarged manner.

Fig. 4 is a perspective view showing a partial structure of the ink jet head in an enlarged manner.

Fig. 5 is an explanatory view showing a partial structure of the ink jet head in an enlarged manner.

Fig. 6 is an explanatory view showing a method of manufacturing the ink jet head.

Fig. 7 is an explanatory view showing a method of manufacturing the ink jet head.

Fig. 8 is a table showing contact angles between the lyophobic material and the piezoelectric material according to the embodiment and pure water.

Fig. 9 is a schematic diagram showing an inkjet printer according to an embodiment.

Description of the reference numerals

1 … ink jet head, 10 … actuator base, 12 … base material, 13 … actuator, 14 … pressure chamber, 15 … lyophobic film, 16 … electrode layer, 17 … pattern electrode, 18 … pattern electrode, 19 … resin cover, B … air chamber, 20 … frame, 30 … nozzle plate, 31 … nozzle, 40 … ink manifold, 60 … flexible printed substrate, 61 … drive IC chip, 100 … ink jet printer, 101 … housing, 102 … medium supply portion, 103 … image forming portion, 104 … medium discharge portion, 105 … conveying device, 106 … control portion, 107 … support portion, 108 … conveying belt, 109 … support plate, 110 … belt roller, 121 … ink discharge path, 122 …, … piezoelectric component, 132 … groove, 133 … laminated piezoelectric element, 134 … ink supply path, 151 … lyophobic material, 36191 mask, 36192 lamp, … LED … lamp, … ink cartridge 202, … head connecting flow path, 204 … circulating pump, 1021 … paper feed cassette, 1041 … paper discharge tray, 1061 … CPU, 1311 … top surface portion, 1312 … side surface portion, 1321 … bottom surface portion, 1322 … side surface portion, a … conveying path.

Detailed Description

Next, an ink jet head 1 as a liquid ejecting head and an ink jet printer 100 as a liquid ejecting apparatus according to a first embodiment will be described with reference to fig. 1 to 8. Fig. 1 is a perspective view showing a schematic structure of the ink jet head 1, and fig. 2 is an exploded perspective view showing a partial structure of the ink jet head 1. Fig. 3 is a sectional view showing a partial structure of the ink-jet head 1 in an enlarged manner. Fig. 4 is a perspective view showing a partial structure of the ink jet head 1 in an enlarged manner, and the resin cover 19 is partially omitted to show an internal structure thereof for the sake of convenience of explanation. Fig. 5 is an explanatory diagram schematically showing the structure of the actuator. In the following description, an orthogonal coordinate system including an X axis, a Y axis, and a Z axis is used. Arrows X, Y, Z indicate three mutually orthogonal directions. The X axis extends along a first direction, which is an arrangement direction of the nozzles, the Y axis extends along a second direction, which is an arrangement direction of the nozzle rows, and the Z axis extends along a third direction, which is a direction in which the droplets are ejected. In the drawings, the structure is appropriately enlarged, reduced, or omitted for convenience of explanation.

The inkjet head 1 includes an actuator base 10, a frame 20, a nozzle plate 30, and a manifold 40. The ink jet head 1 is, for example, an on-demand type ink jet head mounted on an ink jet printer for use, and is a circulation type ink jet head that circulates ink between the ink jet head and an ink cartridge of the ink jet printer. The inkjet head 1 is connected to a flow path at an ink tank as a liquid storage unit provided in the inkjet printer 100, and is disposed in a posture in which the nozzles 31 along the third direction face downward, for example.

The actuator base 10 includes a base 12 serving as an actuator substrate and a plurality of actuators 13 provided on the base 12.

The base material 12 is formed in a square plate shape. The base material 12 is preferably composed of PZT, ceramic, glass, free-cutting ceramic, or a material containing these. For example, two actuators 13 extending in the first direction are provided on one side surface of the base material 12, and a plurality of ink discharge paths 121 are provided between the two actuators 13 at intervals in the first direction. The ink discharge path 121 is a circular hole penetrating the base material 12 in the Z direction, and communicates with a common ink chamber formed in the manifold 40 on the back side of the base material 12.

In addition, the pattern electrode 17 and the lyophobic film 15 are formed on predetermined portions of the main surface 122 of the substrate 12. That is, the main surface 122 of the substrate 12 has a lyophobic region in which the lyophobic film 15 is formed and an electrode region in which an electrode layer constituting the pattern electrode 17 is formed.

The pattern electrode 17 is positioned on the base material 12 and reaches the outside of the frame 20, is connected to the flexible printed board 60 outside the frame 20, and is connected to the driver IC chip 61 mounted on the flexible printed board 60. Further, a protective film may be further formed on the surface of the base material 12.

The pattern electrode 17 is a conductive film formed of a conductive material such as nickel and having a predetermined pattern shape. The pattern electrode 17 is patterned into a predetermined shape as follows: the electrode layer 16 disposed on the side wall surface 132 of the groove 132 of the actuator 13 is led out to a mounting portion such as a drive circuit. For example, the pattern electrode 17 is formed in a region of each actuator 13 opposite to the region where the ink discharge path 121 is arranged. The pattern electrode 17 is formed of a conductive material by a method such as vacuum deposition or electroless plating, and is patterned into a predetermined pattern shape. Further, the pattern electrode 17 may be formed simultaneously with the electrode layer 16.

The actuator 13 includes a plurality of piezoelectric members 131 provided on the base 12. The piezoelectric member 131 is formed by laminating a first piezoelectric body and a second piezoelectric body. Examples of the material of the first piezoelectric body and the second piezoelectric body include lead zirconate titanate (PZT) and lithium niobate (LiNbO)₃) Lithium tantalate (LiTaO)₃) And the like. The first piezoelectric body and the second piezoelectric body are polarized in opposite directions along the thickness direction.

The side surface 1312 of the piezoelectric member 131 has an inclined surface inclined with respect to the second direction and the third direction. That is, the cross section of the piezoelectric member 131 perpendicular to the second direction is formed in a trapezoidal shape. The bottom surface 1321 of the groove 132 is connected to the main surface 122 of the substrate 12 by an inclined side surface 1312.

A plurality of grooves 132 aligned in the first direction are formed in a top surface 1311, which is an end surface of the piezoelectric member 131 facing the nozzle plate 30. That is, the piezoelectric member 131 is formed in a comb-tooth shape, and the pillar-shaped portion formed between the adjacent grooves 132 forms a laminated piezoelectric element 133 as a driving element portion for changing the volume of the groove 132. In other words, the plurality of laminated piezoelectric elements 133 of the piezoelectric member 131, which is a laminated piezoelectric body, are arranged in one direction, and the groove 132 is formed between the adjacent laminated piezoelectric elements 133. The grooves 132 are formed over the entire length of the piezoelectric members 131 in the second direction, respectively. The groove 132 is open on the nozzle plate 30 side. Among the plurality of grooves 132 arranged in the first direction, grooves 132 arranged every two constitute pressure chambers 14, and grooves 132 arranged between the pressure chambers 14 constitute dummy air chambers B.

Ink supply paths 134 are formed on bottom surface portions 1321 of the grooves 132 constituting the pressure chambers 14 arranged every two. The ink supply path 134 is a circular hole penetrating the piezoelectric member 131 and the base 12 in the Z direction, and communicates with a common ink chamber formed in the manifold 40 on the back side of the base 12. Ink is supplied from the ink supply path 134 along the Z direction, which is the depth direction of the groove 132.

The liquid repellent film 15 is formed on the bottom surface 1321 of the groove 132. The liquid repellent film 15 is a layer formed by forming a liquid repellent material 151 having high liquid repellency to a predetermined thickness. For example, as shown in fig. 8, the contact angle, which is the angle formed by the liquid surface and the solid surface of the lyophobic film 15, is larger than the contact angle of PZT. The contact angle of PZT is 70 degrees, and the contact angle of the lyophobic film 15 is 110 degrees. Therefore, the plating liquid forming the electrode is flicked by the lyophobic film 15, and the electrode is not formed on the lyophobic film 15. That is, the region where the lyophobic film 15 is formed constitutes a separation section for separating the electrodes. As the lyophobic material 151, for example, a fluorine-based coating agent such as SF-coat manufactured by AGC corporation can be used.

Electrode layers 16 are formed on both side wall surfaces 1322 of the groove 132. The electrode layer 16 is a conductive film formed of a conductive material such as nickel into a predetermined shape. The electrode layer 16 is formed with a conductive material over the entire surface by a method such as a vacuum deposition method or an electroless nickel plating method, and then is patterned by removing a part of the electrode by laser processing. In the present embodiment, nickel is used as the conductive material of the electrode layer 16, but the present invention is not limited thereto, and may be formed of, for example, gold, copper, or the like. Alternatively, the electrode layer 16 may be formed by laminating two or more films of conductive materials.

The electrode layer 16 is connected to a wiring formed on a circuit board or a flexible wiring board via a pattern electrode 17 formed on the side surface 1312 of the piezoelectric member 131 and the main surface 122 of the base 12, and is further electrically connected to various electronic components such as a driver IC via the circuit board or the flexible wiring board.

Pattern electrode 18 is formed on the side surface 1312 of piezoelectric member 131, which is an inclined surface continuous with groove 132. The pattern electrode 18 is connected to the electrode layer 16 on the side wall surface 1322 of the groove 132, and is connected to the pattern electrode 17 formed on the main surface 122 of the substrate 12.

The pattern electrode 18 is a conductive film formed of a conductive material such as nickel and having a predetermined pattern shape. The pattern electrode 18 is patterned into a predetermined shape as follows: the electrode layer 16 disposed on the side wall surface 132 of the groove 132 of the actuator 13 is led out to a mounting portion such as a drive circuit. The pattern electrode 18 is formed of a conductive material by a method such as vacuum deposition or electroless plating, and is patterned into a predetermined pattern shape. In addition, pattern electrode 18 may be formed simultaneously with electrode layer 16.

The surface of the actuator base 10 has a lyophobic region as a first region where the lyophobic film 15 is formed and an electrode region as a second region where the electrode layer 16 or the pattern electrode 17 is formed. The lyophobic area and the electrode area are respectively arranged at different positions. For example, an electrode region is formed on the surface of the actuator base 10 at a portion where the lyophobic region is not formed.

For example, the lyophobic regions formed by the lyophobic film 15 are formed at predetermined positions on the bottom surface 1321 of the groove 132 of the actuator 13, the top surface 1311 of the laminated piezoelectric element 133, the inclined side surface 1312 of the piezoelectric member 131, and the main surface 122 of the substrate 12.

Electrode regions for forming electrode layer 16 and

pattern electrodes

17 and 18 are formed on side wall surfaces 1322 of groove 132, side surface portions 1312 of piezoelectric element 131 as inclined surfaces, and predetermined portions of main surface 122 of substrate 12. The electrode layer 16 is not formed on the bottom surface 1321 of the groove 132, and the electrode layers 16 formed on both side wall surfaces 1322 are separated from each other.

The inclined surface on the one end side in the second direction of the actuator 13 is covered with a resin cover 19. The other end side of the actuator 13 in the second direction, that is, the ink discharge port 121 side is partially covered with the resin cover 19. Specifically, one side of the groove 132 constituting the pressure chamber 14 in the second direction is closed by the resin cover 19, and the other side is open and communicates with the ink discharge path 121. Both ends of the air chamber B in the second direction are covered and closed by the resin cover 19.

For example, the resin cover 19 is formed by using an adhesive made of an epoxy resin material, and is formed by applying the adhesive to the side surface of the actuator 13 and then thermally curing the adhesive. The surface of the inclined surface on which the wiring is formed is covered, and the opening of the groove 132 is closed to prevent ink from flowing from the groove 132 to the wiring region. That is, one side of the pressure chamber 14 in the second direction is opened to communicate with the ink supply path 134, communicate with the nozzle holes 31, and communicate with the ink discharge port 121. The air chamber B is blocked by the nozzle plate 30 and the resin caps 19 at both ends.

The frame 20 is provided on the actuator base 10, surrounds the outer periphery of the actuator 13, and covers the outer periphery of a partial region of the actuator base 10. The frame 20 is made of, for example, a ceramic material, and is joined to the end surface of the actuator base 10 in the first direction. The frame 20 has an opening smaller than the base material 12 and larger than a region of the base material 12 where the actuator 13 is provided. The frame 20 is bonded to the base material 12, for example, by an adhesive. For example, the frame 20 is bonded to the main surface of the base material 12 on which the liquid-repellent film is formed via a sheet of thermoplastic resin. The frame 20 functions as a guide for guiding a liquid such as ink. An end surface of the opening edge on the upper side in fig. 1 of the frame 20 forms a nozzle facing surface disposed facing the nozzle plate 30. In the present embodiment, the liquid repellent film 15 is also formed on the nozzle facing surface of the frame 20, as an example. The nozzle facing surface of the frame 20 is formed as a flat plane along the XY plane and is on the same plane as the nozzle facing surface of the actuator 13. The nozzle-facing surface of the frame 20 is bonded to the outer periphery of the nozzle plate 30 via an adhesive.

The nozzle plate 30 is formed in a square plate shape. The nozzle plate 30 is made of a resin film such as polyimide, for example. The nozzle plate 30 is formed to have a thickness of 10 to 100 μm, and has a nozzle row formed with a plurality of nozzles 31 penetrating in the thickness direction. The nozzle plate 30 is disposed to face one side in the Z direction so as to cover one side opening in the Z direction of the groove row of the actuator base 10. The nozzles 31 are provided at positions corresponding to the plurality of pressure chambers 14, respectively. That is, the nozzle plate 30 has the nozzles 31 communicating with the pressure chambers constituted by the grooves 132. The nozzle plate 30 is larger than the opening of the frame 20. The nozzle plate 30 is bonded to the frame 20, for example, by an adhesive. The nozzles 31 are formed in two rows corresponding to the pressure chambers. The diameter of the nozzle 31 increases in a direction from the recording medium facing surface toward the pressure chamber. The size of the nozzle 31 is set to a predetermined value according to the ink ejection amount. The nozzle 31 can be formed by performing laser processing using an excimer laser, for example.

The manifold 40 is disposed on one side of the actuator base 10 and constitutes a common ink chamber. The manifold 40 has a supply port that communicates with the common ink chamber and flows ink from the outside into the common ink chamber, and a discharge port that discharges ink from the common ink chamber to the outside. The supply port and the discharge port are connected to the connection flow path.

The inkjet head 1 is integrally assembled with the manifold 40, the actuator base 10, the frame 20, and the nozzle plate 30, and forms an ink flow path inside. The ink was circulated as follows: the ink is supplied from the common ink chamber formed in the manifold 40 to the pressure chamber 14 through the ink supply path 134, and then passes through the pressure chamber 14, and the remaining ink is returned from the ink discharge path 121 to the manifold 40. While part of the ink flows through the pressure chamber 14, the ink is ejected from the nozzle 31 by a change in the volume of the pressure chamber 14, which is controlled in accordance with image data. For example, by applying a voltage to the electrode layer 16 of the adjacent air chamber B with the electrode layer 16 of the pressure chamber 14 set to GND, the volume of the pressure chamber 14 is changed, and liquid droplets are ejected from the nozzle 31 communicating with the pressure chamber 14.

Next, a method of manufacturing the ink jet head 1 according to the present embodiment will be described with reference to fig. 1 to 7. Fig. 6 and 7 are explanatory views showing a patterning process in the method of manufacturing the ink jet head 1 according to the present embodiment. Fig. 6 is an explanatory view showing an electrode forming process for forming an electrode on a side wall surface of the groove, and fig. 7 is an explanatory view showing an electrode forming process for forming an electrode on a side surface portion of the substrate and the actuator.

In the method of manufacturing the ink jet head 1 according to the present embodiment, the plurality of piezoelectric members 131 having the plurality of grooves formed therein are bonded to the plate-shaped base member 12 with an adhesive or the like, and machining is performed using a dicing saw, a slicer or the like to mold the actuator base 10 having the outer shape of a predetermined shape. For example, a plurality of block-shaped base members corresponding to the thickness of the actuator base may be formed in advance and divided to manufacture a plurality of actuator bases 10 having a predetermined shape.

As shown in fig. 6 and Act1 of fig. 7, a lyophobic material 151 cured by UV is applied to the entire surface of the base material 12. Next, as shown in Act2, after the lyophobic material 151 is applied, ultraviolet rays are irradiated from the nozzle plate 30 side to the portion where the electrode is to be formed using the LED lamp 192 for irradiating UV light, thereby curing the portion irradiated with UV. The light to be irradiated is preferably UV light having high linearity, and preferably has a long wavelength of 330nm or more. For example, after the mask 191 is disposed at a portion where the lyophobic film is not formed, that is, a portion where the electrode layer 16 or the

pattern electrodes

17 and 18 are to be formed, UV is irradiated. That is, after a mask is placed on the main surface 122 of the substrate 12 and the side surface 1312 of the piezoelectric member 131 at the portions where the

pattern electrodes

17 and 18 are to be formed, UV irradiation is performed. At this time, by irradiating the piezoelectric member 131 with UV light having high linearity and a long wavelength from the direction in which the nozzle plate 30 is disposed, the top surface 1311 and the bottom surface 1321 of the groove 132 can be irradiated with UV without disposing the mask 191. Thereby, the parts of the main surface 122 and the side surface parts 1312 of the substrate 12 where no mask is formed and the bottom surface parts 1321 and the top surface parts 1311 of the grooves 132 are cured, and the lyophobic film 15 is formed (Act 3). That is, the liquid-repellent film 15 in the cured portion exhibits liquid-repellent properties. Next, as shown in Act4, the lyophobic material 151 in the portion which is not irradiated with UV light and does not exhibit lyophobic property is removed. Then, in the plating method, since the lyophobic film 15 flicks off the plating liquid, the electrode layer 16 or the

pattern electrodes

17 and 18 are formed only on the region of the substrate 12 and the side surface 1312 where the lyophobic film 15 is not formed and the side wall surface 1322 of the groove 132 (Act 5). Further, as shown in fig. 8, since the contact angle of the lyophobic material 151 constituting the lyophobic film 15 is 110 °, the PZT is 70 °, and the contact angle is larger than that of the PZT, the portion where the lyophobic film 15 is formed flicks the plating liquid, and therefore the electrode layer 16 or the

pattern electrodes

17 and 18 are not formed on the lyophobic film 15. Further, an ink supply path 134(Act5) is formed in the bottom of the groove 132 constituting the pressure chamber 14.

As can be seen, the liquid repellent film 15, the electrode layer 16, and the

pattern electrodes

17 and 18 are formed at predetermined positions on the surface of the actuator base 10. Further, by forming the resin cover 19 at a predetermined position, one end side of the pressure chamber 14 and both ends of the air chamber B are closed. Then, the actuator base 10 is assembled to the manifold 40, and the frame 20 is stuck to one side surface of the actuator base 10 by an adhesive sheet of thermoplastic resin.

Further, the nozzle plate 30 is adhesively attached to the actuator base 10 so as to cover the groove 132. At this time, the nozzle 31 is positioned to face the groove 132. Further, as shown in fig. 1, the driver IC chip 61 and the circuit board are connected to the pattern electrode 17 formed on the main surface of the base material 12 via the flexible printed board 60, thereby completing the ink jet head 1.

Next, an inkjet printer 100 having the inkjet head 1 will be described with reference to fig. 9. Fig. 9 is an explanatory diagram showing the configuration of the inkjet printer 100. As shown in fig. 9, the inkjet printer 100 includes a housing 101, a medium supply unit 102, an image forming unit 103, a medium discharge unit 104, a conveyance device 105, and a control unit 106.

The inkjet printer 100 is a liquid ejection device: the image forming process is performed on the sheet P by discharging a liquid such as ink while conveying the recording medium, which is an ejection target, such as the sheet P along a predetermined conveyance path a from the medium supply unit 102 to the medium discharge unit 104 through the image forming unit 103.

The medium supply unit 102 includes a plurality of paper feed cassettes 1021. The medium discharge unit 104 includes a discharge tray 1041. The image forming unit 103 includes a support portion 107 for supporting the sheet, and a plurality of head units 200 arranged above the support portion 107 in an opposed manner.

The support portion 107 includes: a conveyor belt 108 provided in a ring shape in a predetermined region where image formation is performed; a support plate 109 that supports the conveyor belt 108 from the back side; and a plurality of belt rollers 110 disposed on a back side of the conveyor belt 108.

The head unit 200 includes: a plurality of ink-jet heads 1; a plurality of ink cartridges 202 as liquid tanks mounted on the respective ink jet heads 1; a connection flow path 203 for connecting the ink-jet head 1 and the ink cartridge 202; and a circulation pump 204 as a circulation portion. The head unit 200 is a circulation type head unit that circulates liquid.

In the present embodiment, the inkjet head 1 includes four color inkjet heads 1 of cyan, magenta, yellow, and black, and the ink cartridges 202 that contain the inks of the respective colors are provided. The ink cartridge 202 is connected to the inkjet head 1 through a connection flow path 203. The connection channel 203 includes a supply-side channel connected to the supply port of the inkjet head 1 and a recovery-side channel connected to the discharge port of the inkjet head 1.

A negative pressure control device such as a pump, not shown, is connected to the ink cartridge 202. Then, the negative pressure control device performs negative pressure control in the ink cartridge 202 in accordance with the hydraulic head pressure of the ink jet head 1 and the ink cartridge 202, thereby forming the ink supplied to each nozzle of the ink jet head 1 into a meniscus having a predetermined shape.

The circulation pump 204 is an infusion pump formed of a piezoelectric pump, for example. The circulation pump 204 is provided in the supply-side flow path. The circulation pump 204 is connected to a drive circuit of the control unit 106 through a wire. A CPU (Central Processing Unit) 1061 is configured to control the circulation pump 204. The circulation pump 204 circulates the liquid in a circulation flow path including the inkjet head 1 and the ink cartridge 202.

The conveyance device 105 conveys the sheet P along a conveyance path a from the sheet feed cassette 1021 of the medium supply unit 102 to the sheet discharge tray 1041 of the medium discharge unit 104 through the image forming unit 103. The conveying device 105 includes a plurality of guide plate pairs and a plurality of conveying rollers arranged along the conveying path a.

The control unit 106 includes: a CPU1061 as a controller; a ROM (Read Only Memory) that stores various programs and the like; a RAM (Random Access Memory) that temporarily stores various variable data, image data, and the like; and an interface unit which inputs and outputs data from and to the outside.

In the inkjet head 1 and the inkjet printer 100, when driving is performed to eject liquid from the nozzles 31, the control unit 106 applies a driving voltage via the pattern electrodes 17 by the driving circuit, bends and deforms the driving element unit, and ejects liquid droplets from the nozzles 31 by changing the volume of the pressure chambers 14.

According to the above embodiment, an ink jet head that is easy to manufacture can be provided. That is, according to the above embodiment, since the electrode layer is not formed at the position where the lyophobic film 15 is formed, the patterning of the electrode layer 16 can be easily performed. Further, by irradiating with UV light having high linearity, a lyophobic film can be formed at a predetermined position of the groove 132 except for the side surface of the groove 132 with high positional accuracy without using a mask. Further, by using UV light having a long wavelength of 330nm or more, the bottom 1321 of the groove 132 can be irradiated with the UV light. Therefore, the electrodes can be disposed at the predetermined positions with high accuracy, and high ink ejection performance can be ensured.

In addition, according to the above embodiment, since the lyophobic film 15 is also formed on the top surface 1311 of the actuator 13, the adhesive can be prevented from overflowing when the adhesive is applied. Further, since the adhesive can be suppressed from overflowing, the thickness of the adhesive can be controlled in the adhesion of the nozzle plate 30 and the actuator 13, and the distance from the nozzle plate 30 can be controlled. Therefore, the heights of the stacked piezoelectric elements 133 constituting the plurality of driving element portions can be aligned, and the inclination or distortion of the nozzle plate 30 can be suppressed. In the above embodiment, the liquid-repellent film 15 is formed also on the nozzle-facing surface of the frame 20, whereby the thickness of the adhesive layer on the frame 20 can be controlled in addition to the thickness of the adhesive layer on the actuator 13. Further, for example, by bonding the base material 12 to the main surface of the base material 12 via an adhesive sheet of thermoplastic resin, the size from the main surface of the base material 12 to the nozzle-facing surface of the frame 20 can be controlled, and therefore, the height of the adhesive between the nozzle plate 30 and the frame 20 can be controlled, and therefore, the height of the actuator 13 and the height of the frame 20 with respect to the nozzle surface can be easily aligned, and the flatness of the nozzle plate 30 can be ensured. Further, since no electrode is provided on the bottom surface portion of the groove 132, the bottom portion of the groove 132 can be made thin.

According to the above embodiment, the ink supply path 134 is formed in the bottom surface 1321 of the groove 132 forming the pressure chamber 14, so that the ink can be supplied from the bottom surface of the groove 132. Therefore, by closing both ends of the groove 132 constituting the air chamber B and setting the electrode constituting the groove 132 of the pressure chamber 14 to which the ink is supplied as GND, electrolysis or redox reaction can be suppressed. That is, in the configuration in which ink is supplied from the common ink chamber to the pressure chamber in the longitudinal direction thereof, when a voltage is applied to the electrodes of the pressure chamber, a voltage difference may be generated in the common ink chamber, and when an ink having conductivity such as an aqueous ink is used, electrolysis may occur due to a potential difference, and the ink may not be ejected. However, according to the above embodiment, by setting the electrode of the groove 132 constituting the pressure chamber 14 to GND and applying a voltage to the dummy air chamber B, the actuator 13 can be driven without applying a voltage to the ink and without generating a potential difference. Therefore, even when an ink having high conductivity or an oxidizing agent or a reducing agent is used, electrolysis or redox reaction does not occur.

The present invention is not limited to the above-described embodiments, and constituent elements can be modified and embodied in the implementation stage without departing from the scope of the invention.

In the above-described embodiment, the ink jet head 1 of the so-called side-shooter type is shown, but is not limited thereto. For example, it is also applicable to an end-shooter type ink jet head. For example, the following may be configured: the plate-like member as the first member blocks the comb-teeth-shaped actuator base having the grooves that open in two different directions, from a surface facing the nozzle plate in a different predetermined direction.

In the above embodiment, the piezoelectric member 131 including the plurality of grooves 132 is disposed on the main surface portion of the base 12, but the present invention is not limited thereto. For example, an actuator may be provided on an end face of the base material 12. The number of nozzle rows is not limited to the above embodiment, and one or three or more rows may be provided.

Further, the example of forming the lyophobic film 15 by irradiating the bottom surface 1321 and the top surface 1311 in the groove 132 with UV light without using a mask is shown, but the present invention is not limited to this, and for example, patterning may be performed by arranging a mask as necessary when irradiating the bottom surface 1321 and the top surface 1311 with UV light.

In the above embodiment, the actuator base 10 is shown in which the base 12 is provided with the piezoelectric laminate constituted by the piezoelectric member 131, but the present invention is not limited to this. For example, the actuator base 10 may be formed of only a piezoelectric member without using a substrate. Alternatively, one piezoelectric member may be used instead of two piezoelectric members.

The liquid to be discharged is not limited to ink for printing, and may be, for example, a device for discharging a liquid containing conductive particles for forming a wiring pattern of a printed wiring board.

In addition, although the above-described embodiments have shown the example in which the ink jet head is used in a liquid ejecting apparatus such as an ink jet recording apparatus, the present invention is not limited to this, and can be used in, for example, a 3D printer, an industrial manufacturing apparatus, and a medical application, and can achieve reduction in size, weight, and cost.

According to at least one embodiment described above, a liquid ejecting head which can be easily manufactured can be provided.

Furthermore, although several embodiments of the present invention have been described, these embodiments are merely provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Claims

1. A liquid ejecting head includes:

a nozzle plate formed with nozzles;

an actuator disposed opposite to the nozzle plate and having a groove that constitutes a plurality of pressure chambers communicating with the nozzles;

a liquid repellent film formed on a predetermined first region of a surface of the actuator; and

and an electrode layer formed in a second region different from the first region in a surface of the actuator.

2. The liquid ejection head according to claim 1,

the actuator is arranged on the base material and provided with a plurality of driving element parts, and the groove is formed among the plurality of driving element parts;

the electrode layer is formed on a predetermined portion of the main surface of the substrate and the side surface of the actuator and the side wall surface of the groove, respectively;

the lyophobic film is formed on a portion different from the predetermined portion among the main surface of the substrate and the side surface portion of the actuator, and on the bottom surface portion of the groove.

3. The liquid ejection head according to claim 1 or 2,

a supply passage for supplying a liquid to the pressure chamber is formed in a bottom surface portion of the groove constituting the pressure chamber.

4. The liquid ejection head according to claim 1 or 2,

the lyophobic film is formed on an opposite surface of the actuator to the nozzle plate.

5. The liquid ejection head according to claim 3,

6. The liquid ejection head according to claim 1 or 2,

the liquid ejecting head includes a frame surrounding the actuator and bonded to the nozzle plate;

a liquid repellent film is formed on an opposite surface of the frame to the nozzle plate.

7. The liquid ejection head according to claim 3,

8. The liquid ejection head according to claim 4,

9. The liquid ejection head according to claim 5,