CN111204131A

CN111204131A - Ink jet head and ink jet apparatus

Info

Publication number: CN111204131A
Application number: CN201910770027.1A
Authority: CN
Inventors: 铃木伊左雄
Original assignee: Toshiba TEC Corp
Current assignee: Toshiba TEC Corp
Priority date: 2018-11-22
Filing date: 2019-08-20
Publication date: 2020-05-29
Anticipated expiration: 2039-08-20
Also published as: JP2020082492A; CN111204131B

Abstract

The invention provides an ink jet head and an ink jet apparatus, which can improve the durability. An inkjet head according to an embodiment includes an electrode provided in an ink flow path, an insulating layer, and a conductive layer. The insulating layer is made of an insulating material and is disposed on a surface of the electrode on the ink flow path side. The conductive layer is made of a conductive material, is disposed on the surface of the insulating layer on the ink flow path side, and is grounded.

Description

Ink jet head and ink jet apparatus

Technical Field

Embodiments of the present invention relate to an inkjet head and an inkjet apparatus.

Background

The following structures are known: an ink jet head for discharging a liquid includes a nozzle plate having a plurality of nozzles and a base constituting a flow path including a pressure chamber communicating with the nozzles, and electrodes are arranged in the flow path. In an inkjet head, there is a demand for printing on various printing media, and since there is a demand for coping with various inks, an electrical protective layer may be provided on an electrode so that the electrode and the ink do not come into contact with each other. In such an ink jet head, when charges are accumulated on the surface of the insulating film, the durability of the insulating layer may be impaired by an electrochemical reaction with ink.

Disclosure of Invention

The present invention provides an ink jet head and an ink jet apparatus capable of improving durability.

An ink jet head includes: an electrode provided in the ink flow path; an insulating layer made of an insulating material and disposed on a surface of the electrode on the ink flow path side; and a conductive layer made of a conductive material, disposed on the surface of the insulating layer on the ink flow path side, and grounded.

An inkjet device includes an inkjet head, and the inkjet head includes: an electrode provided in the ink flow path; an insulating layer made of an insulating material and disposed on a surface of the electrode on the ink flow path side; and a conductive layer made of a conductive material, disposed on the surface of the insulating layer on the ink flow path side, and grounded, wherein the ink jet device is connected to ground and grounded to ground connected to the ground to which the conductive layer is grounded at the same potential.

Drawings

Fig. 1 is an exploded perspective view of an ink jet head according to a first embodiment.

Fig. 2 is a sectional view showing a structure of a part of the ink jet head.

Fig. 3 is an explanatory view showing a structure of a part of the ink jet head and a manufacturing method thereof.

Fig. 4 is an explanatory view of the inkjet recording apparatus according to this embodiment.

Fig. 5 is a sectional view of a structure of a part of an ink jet head according to another embodiment.

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

Description of the reference numerals

1 … ink jet head; 10 … a base; 11 … ink flow path; 12 … a substrate; 12a … wiring pattern; 12b … supply port; 12c … discharge port; 13 … actuator; 13a … piezoelectric element; 13b … piezoelectric element; 14 … grooves; 15 … a drive element; 16 … electrodes; 17 … an insulating layer; 18 … a conductive film; 19 … a protective layer; 20 … a nozzle plate; a 21 … nozzle; 21a … nozzle row; 30 … frame members; a 40 … manifold; 41 … common path; 42 … supply path; 43 … discharge path; 50 … circuit substrate; 51 … FCP; 52 … driver IC; 100 … inkjet devices; 111 … casing; 112 … media supply; 112a … paper supply cassette; 113 … an image forming section; 114 … media discharge; 114a … paper discharge tray; 115 … conveying device; 116 … control section; 116a … CPU; 117 … support portions; 118 … conveyor belt; 119 … a support plate; 120 … belt rollers; 121a to 121h … guide plate pairs; 122a to 122h …; 130 … head element; 132 … ink cartridges; 133 … connecting the flow paths; 133a … supply flow path; 133b … recovery flow path; 134 … circulating pump; a1 … conveying path; a C1 … pressure chamber; a C2 … ink chamber; GND1 … ground; GND2 … ground.

Detailed Description

Next, the structure of the ink jet head 1 and the ink jet apparatus 100 according to the first embodiment will be described with reference to fig. 1 to 6. Fig. 1 is an exploded perspective view of an inkjet head according to an embodiment, and fig. 2 is a sectional view of the inkjet head. Fig. 3 is an explanatory view showing a structure of a part of the ink jet head and a manufacturing method thereof. For convenience of explanation, the drawings are appropriately enlarged, reduced, or omitted in structure.

The ink jet head 1 shown in fig. 1 to 4 includes a base 10, a nozzle plate 20 having a plurality of nozzles 21, a frame member 30, a manifold 40, and a pair of circuit boards 50. The inkjet head 1 is a so-called side-shooter (side-shooter) type shared mode (shared wall) type inkjet head. In the present embodiment, an example in which each of the pair of nozzle rows 21A, the actuator 13, and the circuit board 50 is provided is shown as an example, but the present invention is not limited thereto, and the number of the respective components may be changed as appropriate.

As shown in fig. 1 to 3, the base 10 includes a substrate 12 and an actuator 13.

The substrate 12 is formed in a square plate shape having a predetermined thickness. The substrate 12 is preferably made of PZT, ceramic, glass, free-cutting ceramic, or a material containing them.

A predetermined wiring pattern 12a (wiring electrode) is formed on the nozzle plate 20 side surface of the substrate 12. The wiring pattern 12a is formed by a method such as a vacuum vapor deposition method or an electroless nickel plating method, and is formed into a pattern having a predetermined shape by etching or laser processing.

The substrate 12 is provided with a supply port 12b and a discharge port 12 c. The supply port 12b is a through hole for communicating the common path 41 of the manifold 40 and causing ink to flow from the common path 41 of the manifold 40 into the ink chamber C2. The discharge port 12C is a through hole in the common path 41 for communicating with the manifold 40 and discharging ink from the ink chamber C2 to the common path 41 of the manifold 40.

On the opposite surface of the substrate 12 facing the nozzle plate 20, actuators 13 are provided at predetermined positions facing the nozzle rows 21A, respectively. In the present embodiment, a pair of actuators 13 extending in the first direction is formed. The actuator 13 is formed of, for example, a laminated piezoelectric body in which two piezoelectric members are laminated. The actuator 13 is configured in a comb-tooth shape, and has a plurality of slots 14 that are alternated and a plurality of driving elements 15 that are arranged between the plurality of slots 14.

The piezoelectric member constituting the actuator 13 is formed by, for example, polarizing two

piezoelectric members

13a and 13b made of a PZT (lead zirconate titanate) -based piezoelectric ceramic material in mutually opposite polarization directions and bonding them via an adhesive layer.

The plurality of grooves 14 are arranged at positions facing the nozzles 21, and are aligned in a first direction which is a row direction of the nozzle row 21A. The wall-like portion formed between the adjacent grooves 14 constitutes a drive element 15 that changes the volume of the groove 14.

Each groove 14 is disposed to face the nozzle 21, and constitutes a pressure chamber C1 communicating with the nozzle 21. The electrode 16, the insulating layer 17 covering the surface of the electrode 16, and the conductive film 18 as a conductive layer covering the surface of the insulating layer 17 are stacked on the inner wall of the pressure chamber C1 to form a protective structure.

The electrode 16 is a metal film formed on the bottom wall and the side wall of the groove 14, and is a conductive film made of a conductive material such as nickel. The electrodes 16 are formed from the pressure chambers C1 up to the upper surface of the substrate 12, and are connected to the wiring pattern 12 a. The electrode 16 may be formed of gold, copper, or the like, for example. Alternatively, two or more kinds of conductive films may be stacked.

The insulating layer 17 is a film made of an insulating material, and covers the entire surface of the electrode 16 on the pressure chamber C1 side, that is, the entire surface of the contact surface. In the present embodiment, the insulating layer 17 is formed of parylene, for example. The thickness of the insulating layer 17 is, for example, about 3 μm to 5 μm.

The conductive film 18 covers the entire surface of the insulating layer 17 on the pressure chamber C1 side, that is, the contact surface. The conductive film 18 is formed by sputtering or the like, and is made of Al, Ni, or the like, for example. The conductive film 18 is electrically connected to the ground GND 1. The conductive film 18 is not in contact with the electrode 16. The conductive film 18 may be thin as long as it covers the surface of the insulating layer 17. For example, the film thickness of the conductive film 18 is about 0.5 μm, for example.

The nozzle plate 20 is disposed to face one side of the base 10. The nozzle plate 20 is formed in a rectangular plate shape having a thickness of about 10 μm or more and 100 μm or less. The nozzle plate 20 is provided with a nozzle row 21A having a plurality of nozzles 21 penetrating in the thickness direction. In the present embodiment, for example, 2 nozzle rows 21A are formed. The nozzles 21 are provided at positions corresponding to the plurality of pressure chambers C1, respectively. That is, the nozzle plate 20 has the nozzle 21 communicating with the pressure chamber C1 formed by the groove 14.

The frame member 30 is formed in a square frame shape, for example. The frame member 30 is sandwiched between the base 10 and the nozzle plate 20, surrounds the outer periphery of the actuator 13 of the base 10, and forms an ink chamber C2 communicating with the pressure chamber C1. The actuator 13 of the base 10 is covered with the nozzle plate 20 and the frame member 30.

As shown in fig. 1 and 2, the manifold 40 is provided on the other side of the base 10, that is, on the opposite side of the nozzle plate 20. The manifold 40 is, for example, formed in a block shape, and has a common passage 41 formed therein as a part of the ink flow path 11. The common path 41 includes a supply path 42 communicating with the supply port 12b of the base 10 and a discharge path 43 communicating with the discharge port 12 c.

The pair of circuit boards 50 are disposed on, for example, a pair of side walls on both sides in the width direction of the manifold 40. Various mounting components are mounted on the circuit board 50. The circuit board 50 includes, for example, an FCP (thin film carrier package) 51 on which predetermined wirings are formed, and is connected to the board 12 through an FCP 51. The FCP51 is mounted with a driver IC52, for example. Therefore, the driver IC52 is connected to the electrode 16 of the pressure chamber via the wiring or wiring pattern 12a of the FCP 51.

The ink jet head 1 configured as described above is provided with the ink flow path 11, and the ink flow path 11 includes the plurality of pressure chambers C1 communicating with the nozzles 21, the ink chamber C2 communicating with the plurality of pressure chambers C1, and the common path 41 of the manifold 40.

Fig. 3 is an explanatory view showing a part of the method of manufacturing the ink jet head 1. As shown in fig. 3, in the method of manufacturing the ink jet head 1 according to the present embodiment, the electrode 16 is formed on the inner wall of the groove 14 of the actuator 13 (ACT11), the insulating layer 17(ACT12) is formed so as to cover the entire surface of the contact surface on the pressure chamber C1 side of the electrode 16, that is, the surface on the ink flow path 11 side, and further, Al, Ni, or the like is formed by sputtering or the like so as to cover the entire surface of the contact surface on the pressure chamber C1 side of the insulating layer 17, thereby forming the conductive film 18(ACT 13). Then, the conductive film 18 is electrically connected to the ground GND1, thereby completing the protection configuration. Then, the nozzle plate 20 is disposed so that the frame member 30 faces the susceptor 10, and the susceptor 10, the frame member 30, and the nozzle plate 20 are joined (ACT 14).

Next, an ink jet device 100 having the ink jet head 1 will be described with reference to fig. 4. Fig. 4 is an explanatory diagram showing the structure of the ink jet apparatus 100. As shown in fig. 4, the inkjet device 100 includes a housing 111, a medium supply unit 112, an image forming unit 113, a medium discharge unit 114, a conveying device 115, and a control unit 116.

The ink jet apparatus 100 is an ink jet printer, and performs an image forming process on a sheet P by discharging a liquid such as ink while conveying a recording medium as an ejection target, for example, the sheet P, along a predetermined conveyance path a1 from a medium supply unit 112 to a medium discharge unit 114 through an image forming unit 113.

The medium supply unit 112 includes a plurality of paper feed cassettes 112 a. The medium discharge unit 114 includes a paper discharge tray 114 a. The image forming unit 113 includes a support unit 117 for supporting the sheet, and a plurality of head units 130 arranged above the support unit 117 to face each other.

The support section 117 includes a conveyor belt 118 provided in an endless shape in a predetermined region where image formation is performed, a support plate 119 supporting the conveyor belt 118 from the back side, and a plurality of belt rollers 120 provided on the back side of the conveyor belt 118.

The head unit 130 includes a plurality of inkjet heads 1, a plurality of ink cartridges 132 as liquid cartridges attached to the respective inkjet heads 1, a connection passage 133 connecting the inkjet heads 1 and the ink cartridges 132, and a circulation pump 134 as a circulation unit. The head unit 130 is a head unit that circulates liquid in a circulation flow path that passes through the inkjet head 1 and the ink cartridge 132.

In the present embodiment, the inkjet head 1 includes four color inkjet heads 1C, 1M, 1Y, and 1B of cyan, magenta, yellow, and black, and the

ink cartridges

132C, 132M, 132Y, and 132B as the ink cartridges 132 that store the inks of the respective colors. The ink cartridge 132 is connected to the inkjet head 1 through a connection flow path 133. The connection channel 133 includes a supply channel 133a connected to the primary side of the ink channel 11 of the inkjet head 1, and a recovery channel 133b connected to the secondary side of the ink channel 11 of the inkjet head 1.

The ink cartridge 132 is connected to a negative pressure control device such as a pump, not shown. Then, the negative pressure control device controls the negative pressure in the ink cartridge 132 in accordance with the head values of the ink jet head 1 and the ink cartridge 132, thereby forming the ink supplied to each nozzle of the ink jet head 1 into a meniscus having a predetermined shape.

The circulation pump 134 is a liquid feeding pump composed of, for example, a piezoelectric pump. The circulation pump 134 is provided in the supply flow path 133 a. The circulation pump 134 is connected to a drive circuit of the control unit 116 by a wire, and is configured to be controllable by control of a CPU (Central processing unit) 116 a. The circulation pump 134 circulates the liquid in a circulation flow path including the inkjet head 1 and the ink cartridge 132. The circulation flow path is grounded so that electric charges are not accumulated in the ink.

The ink jet device 100 is connected to ground GND 2. The ground GND2 is connected to the ground GND1 to which the conductive film 18 of the inkjet head 1 is connected. Therefore, the ground GND2 of the inkjet device 100 and the ground GND1 of the conductive film 18 have the same potential.

The conveying device 115 conveys the sheet P along a conveying path a1 from the sheet feed cassette 112a of the medium feeding unit 112 to the sheet discharge tray 114a of the medium discharging unit 114 through the image forming unit 113. The conveyance device 115 includes a plurality of guide plate pairs 121a to 121h and a plurality of conveyance rollers 122a to 122h arranged along the conveyance path a 1.

The control unit 116 includes a CPU116a as a controller, a ROM (Read only memory) for storing various programs and the like, a RAM (Random access memory) for temporarily storing various variable data, image data and the like, and an interface unit for inputting and outputting data from and to the outside.

In the ink jet head 1 and the ink jet device 100 configured as described above, when driving to discharge liquid from the nozzles 21, the control unit 116 applies a driving voltage via the driving IC52 to deform the driving element 15, thereby changing the volume of the pressure chamber C1 and discharging ink droplets from the nozzles 21.

The ink jet head 1 and the ink jet device 100 according to the present embodiment can improve the durability of the insulating layer 17 because the conductive film 18, which is the liquid contact surface of the ink, is electrically grounded and chemical reaction with the ink and the like are less likely to occur.

Further, by electrically grounding the circulation flow path, which is the flow path of the ink in the ink jet device 100, accumulation of charges in the ink is prevented, and durability is improved.

In the ink jet device 100, the ground GND1 of the conductive film 18 on the insulating layer 17 and the ground GND2 of the ink jet device 100 that is grounded are connected to each other and set to the same potential, so that even when ink adhering to the inside of the ink jet device 100 and ink inside the ink jet head 1 come into contact with each other, a potential difference does not occur in the ink, and therefore, it is possible to prevent problems from occurring in the ink or the ink jet head 1.

According to the above embodiment, the electrochemical reaction of the insulating layer 17 can be prevented, and the durability can be improved.

The present invention is not limited to the configuration of the above embodiment, and can be implemented with appropriate modifications. For example, the insulating layer 17 may use SiO in addition to parylene₂TEOS (tetraethoxysilane), and the like.

For example, although the first embodiment described above shows an example in which the surface of the electrode facing the pressure chamber C1 and the ink chamber C2 is covered with the protective structure of the insulating layer 17 and the conductive film 18, the protective layer 19 may be further formed on the entire surface of the contact surface, which is the surface on the pressure chamber side of the conductive film 18, as in the inkjet head 1A according to another embodiment, as shown in fig. 5 and 6, for example.

The protective layer 19 is a film made of an insulating material, and covers the entire surface of the conductive film 18 on the pressure chamber C1 side, that is, the entire surface of the contact surface. In this embodimentIn the formula, the protective layer 19 is made of a material that is less reactive with the ink used, for example. The protective layer 19 may also be made of, for example, parylene or SiO, other than the insulating layer 17₂And a metal material other than an insulating material such as TEOS. The thickness of the protective layer 19 is, for example, about 3 μm to 5 μm.

Fig. 6 is an explanatory view showing a part of the method of manufacturing the ink jet head 1A. In the method of manufacturing the ink jet head 1A according to the present embodiment, Act11 to Act13 are performed in the same manner as in the ink jet head 1 according to the first embodiment shown in fig. 3. Specifically, the electrode 16 is formed on the inner wall of the groove 14 of the actuator 13 (Act11), the insulating layer 17 is formed so as to cover the entire surface of the contact surface on the pressure chamber C1 side of the electrode 16(Act 12), and Al, Ni, or the like is formed by sputtering or the like so as to cover the entire surface of the contact surface on the pressure chamber C1 side of the insulating layer 17, whereby the conductive film 18 is formed (Act13), and the conductive film 18 is electrically connected to the ground GND 1. Then, as shown in fig. 6, the protective layer 19 is formed so as to cover the entire surface of the contact surface of the conductive film 18 on the pressure chamber C1 side (ACT 15). Then, the nozzle plate 20 is disposed so that the frame member 30 faces the susceptor 10, and the susceptor 10, the frame member 30, and the nozzle plate 20 are joined (ACT 16).

The other structure is the same as the ink jet head 1 according to the first embodiment. The present embodiment can also obtain the same effects as those of the first embodiment.

That is, the ink jet head 1A electrically grounds the protective layer 19 that is the liquid contact surface of the ink, and thus chemical reaction with the ink and the like are less likely to occur, and thus the durability of the insulating layer 17 can be improved. In addition, according to the present embodiment, since the conductive film 18 can be covered and protected by the protective layer 19, the restriction on the type of the general-purpose ink can be alleviated, and various inks can be applied. That is, for example, ink that is not suitable for contacting liquid on the conductive film 18, such as dissolving metal, can be used, and the versatility is high.

In the present embodiment, the ink jet device 100 is grounded to the ground GND2, and the ground GND1 of the conductive film 18 and the ground GND2 of the ink jet device 100 are connected to each other and set to the same potential, so that even when ink adhering to the inside of the ink jet device 100 and ink inside the ink jet head 1 come into contact with each other, a potential difference does not occur in the ink, and thus, it is possible to prevent a problem from occurring in the ink or the ink jet head 1.

The ink jet head 1 of the so-called side channel type is exemplified in the above embodiment, but is not limited thereto. For example, the present invention can be applied to a tail tank type ink jet head as another embodiment.

The liquid to be ejected is not limited to ink, and a liquid other than ink may be ejected. The liquid ejecting apparatus for ejecting a liquid other than ink may be, for example, an apparatus for ejecting a liquid containing conductive particles for forming a wiring pattern of a printed wiring board.

The inkjet head 1 may have a structure other than the above structure, for example, a structure in which a vibration plate is deformed to eject ink droplets, a structure in which ink droplets are ejected from nozzles by heat energy of a heater or the like, or the like.

In the above-described embodiments, the example in which the liquid ejecting apparatus is applied to the inkjet recording apparatus is shown, but the invention is not limited thereto. For example, the present invention can be used for 3D printers, industrial manufacturing machines, and medical applications, and can achieve reduction in size, weight, and cost.

According to at least one of the embodiments described above, the durability of the protective layer covering the electrode can be improved.

While several embodiments of the invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications are included in the scope and spirit of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Claims

1. An ink jet head, comprising:

an electrode provided in the ink flow path;

an insulating layer made of an insulating material and disposed on a surface of the electrode on the ink flow path side; and

and a conductive layer made of a conductive material, disposed on the surface of the insulating layer on the ink flow path side, and grounded.

2. An ink jet head according to claim 1,

the ink flow path has a pressure chamber communicating with a nozzle for ejecting ink,

the electrode is connected to an actuator provided in the pressure chamber,

the insulating layer covers a surface of the electrode on the ink flow path side,

the conductive layer covers a surface of the insulating layer on the ink flow path side.

3. An ink jet head according to claim 1,

the ink jet head includes a protective layer that covers a surface of the conductive layer on the ink flow path side.

4. An ink jet head according to any of claims 1 to 3,

the insulating layer is formed of parylene.

5. An ink jet head according to any of claims 1 to 3,

the film thickness of the insulating layer is 3 [ mu ] m or more and 5 [ mu ] m or less.

6. An ink jet head according to claim 4,

7. An ink jet head according to any of claims 1 to 3,

the film thickness of the conductive layer was 0.5 μm.

8. An ink jet head according to claim 4,

the film thickness of the conductive layer was 0.5 μm.

9. An ink jet device is characterized by comprising an ink jet head,

the ink jet head includes:

an electrode provided in the ink flow path;

a conductive layer made of a conductive material, disposed on a surface of the insulating layer on the ink flow path side, and grounded,

the ink ejection device is connected to ground and grounded to ground connected to ground to which the conductive layer is grounded at the same potential.

10. InkJet device according to claim 9,