JP2001219557A - Ink jet head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reliable image having high image quality by reducing crosstalk through a simple arrangement. SOLUTION: In the head 1 for writing a character or an image by ejecting an ink drop from each nozzle 9 toward a recording medium in response to a control signal inputted to each individual electrode 15 formed on an insulation layer 14 which is formed on a conductive substrate 13, the substrate 13 is connected with the ground level in order to prevent induction of a potential in the individual electrode 15 through the substrate 13 at the time of conducting the individual electrode 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and an ink jet recording apparatus, and more particularly to a method for preventing a crosstalk from occurring and stably forming a high quality image.

[0002]

2. Description of the Related Art The non-impact recording method has attracted attention for office use and the like because noise generation during recording is small enough to be ignored. Among them, the ink jet recording method capable of high-speed recording and capable of performing recording on plain paper without requiring a special fixing process is an extremely effective method, and various methods have been conventionally proposed, commercialized and put to practical use. Such an ink jet recording method is to perform recording by flying small droplets of ink as a recording liquid and attaching the droplets to a recording medium, and to control a method of generating the droplets of the recording liquid and a flying direction of the droplets. Are roughly divided into several types according to the control method.

[0003] The first method is a teletype (Telet).
ype) method, the generation of small droplets of the recording liquid is performed by electrostatic attraction, the generated small droplets are subjected to electric field control according to a recording signal, and the small droplets are selectively attached to a recording medium. It is for recording. Specifically, an electric field is applied between the nozzle and the accelerating electrode to discharge a uniformly charged droplet of the recording liquid from the nozzle, and the discharged droplet can be electrically controlled in accordance with a recording signal. The droplets fly between the xy deflection electrodes and selectively deposit small droplets on the recording medium by a change in the intensity of the electric field.

[0004] The second method is called a Sweet method, in which a small droplet of a recording liquid whose charge amount is controlled by a continuous vibration generation method is generated, and the small droplet whose charge amount is controlled is applied to a uniform electric field. In this case, the recording is performed on the recording medium by flying between the deflection electrodes on which recording is performed. Specifically, a charging electrode to which a recording signal is applied is disposed at a predetermined distance in front of an orifice (ejection port) of a nozzle, which is a part of a recording head provided with a piezoelectric vibrating element. Then, by applying an electric signal of a constant frequency to the piezoelectric vibrating element, the piezoelectric vibrating element is mechanically vibrated,
A small droplet of the recording liquid is ejected from the orifice. At this time,
Charge is electrostatically induced by the charging electrode to the ejected droplet,
The droplet is charged with a charge amount according to the recording signal. When the droplet having a controlled charge amount flies between the deflection electrodes to which a constant electric field is uniformly applied, the droplet is deflected according to the added charge amount, and only the droplet carrying the recording signal remains on the recording medium. It will adhere.

The third method is called a Hertz method, in which an electric field is applied between a nozzle and a ring-shaped charging electrode, and recording is performed by generating and atomizing small droplets of a recording liquid by a continuous vibration generation method. It is a method. That is, the intensity of the electric field applied between the nozzle and the charging electrode is modulated in accordance with the recording signal to control the atomization state of the small droplet, and the recording is performed with the gradation of the recorded image.

The fourth method is called the "Stemme" method, in which small droplets of a recording liquid are ejected and ejected from an ejection port in accordance with a recording signal for recording. That is, S
In the temme method, an electric recording signal is applied to a piezoelectric vibrating element (piezoelectric element) attached to a recording head having a discharge port for discharging a recording liquid to change the vibration into mechanical vibration of the piezoelectric vibrating element. In accordance with the vibration, small droplets of the recording liquid are ejected and ejected from the ejection ports and adhere to the recording medium.

The fifth method is called a bubble jet method (thermal ink jet method), which heats ink in a liquid chamber to generate air bubbles, causing a pressure rise in the ink, and ejecting the ink from a fine capillary nozzle. It is to be recorded.

Further, in recent years, similar to the bubble jet method, a method capable of achieving high density and high integration using a silicon substrate is disclosed in, for example, JP-A-4-52214 or JP-A-3-2214.
No. 93141, JP-A-6-50601, JP-A-9-300269, and the like. This method is a recording method in which a liquid chamber and a vibration plate are formed on a silicon substrate by etching, a voltage is applied between electrodes of the substrate and the vibration plate, and the vibration plate is bent by electrostatic force to eject ink. Further, as shown in, for example, JP-A-6-50601, a diaphragm is provided in a part of the ink liquid chamber, an electrode substrate facing the diaphragm is provided with a small gap, and a common electrode is formed on the diaphragm. , Providing individual electrodes on the electrode substrate,
The diaphragm is driven stably, and the density and thickness of the head are reduced. By using a substrate such as silicon, which is easily etched, as the electrode substrate, a groove for forming a minute gap between the diaphragm and the electrode substrate and an individual electrode located at the bottom thereof can be easily formed. Since the silicon substrate forming this electrode substrate is a semiconductor, the individual electrodes are formed on an insulating layer such as SiO ₂ . Japanese Patent Application Laid-Open No. 9-300629 discloses that, when connecting a terminal of an individual electrode, a terminal of a common electrode, and a flexible printed wiring board (hereinafter, referred to as FPC) for inputting a control signal, a terminal portion of the individual electrode is used. The FPC is thermocompression-bonded simultaneously by changing the amount of heating and the amount of pressure applied to the terminal portion of the common electrode.

[0009]

As described above, when a voltage is applied between the substrate and the electrode of the diaphragm and ink is ejected by flexing the diaphragm by electrostatic force, the two electrodes of the individual electrode and the common electrode are used. In addition to the capacitor formed between the electrodes, a capacitor is also formed between the individual electrode and the silicon substrate substrate that sandwiches the insulating layer. When a voltage is applied to the individual electrode, the potential is applied to the individual electrode that is not driven through the substrate. This causes a so-called crosstalk in which the diaphragm not driven by this potential also vibrates.

In the case of the bubble jet method, a heating resistor is formed on a silicon substrate, and the capacitance generated between the heating resistor and the substrate of the silicon substrate does not cause any particular problem. The cross talk was not a problem in the case of forming the piezoelectric body because the capacitance of the piezoelectric body was much larger than the capacitance between the substrate and the substrate. Since a small capacitance is formed between the substrates with a small gap, the capacitance with the substrate has a great effect, and crosstalk becomes a problem, and the printed image quality deteriorates due to the crosstalk.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet head and an ink jet recording apparatus which can improve such disadvantages, reduce crosstalk with a simple structure, and obtain highly reliable and high quality images. is there.

[0012]

According to the present invention, there is provided an ink jet head comprising: an insulating layer formed on a conductive substrate; and a control signal input to an individual electrode formed on the insulating layer. In an ink jet head for drawing characters and images by spraying ink droplets from a nozzle onto a recording medium, the substrate is connected to a ground level.

It is preferable that a ground level connection substrate having a conductive pattern is bonded to the substrate with a conductive material. It is preferable to use a conductive adhesive as the conductive material.

It is desirable to provide a substrate positioning means on the ground level connection substrate.

An ink jet recording apparatus according to the present invention has an ink jet head.

According to a second ink jet recording apparatus of the present invention, each of the nozzles is controlled by a control signal input to an insulating layer formed on a conductive substrate and an individual electrode formed on the insulating layer. At least a part of a substrate of an ink jet head for drawing characters and images by spraying ink droplets on a recording medium is directly connected to a ground level.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet head (hereinafter referred to as a head) of the present invention has a head body in which a liquid chamber substrate, a diaphragm substrate and an electrode substrate are laminated by a direct bonding method such as an adhesive or anodic bonding, and an electrode. A backside connection substrate joined to the backside of the substrate with a conductive material. A printed circuit board for driving the head is connected to the electrodes of the electrode substrate, and an external connection wiring is connected to the electrodes of the substrate for connecting the back surface.

The liquid chamber substrate is provided with a plurality of nozzles. The vibrating plate substrate has a vibrating plate, and a liquid chamber substrate and a vibrating plate of the vibrating plate substrate form a liquid chamber communicating with a nozzle and a common liquid chamber communicating with each liquid chamber. The electrode substrate is made of a conductor or semiconductor and has conductivity, an insulating layer formed on the substrate, and formed on the insulating layer, facing the diaphragm with a certain small gap. There are provided individual electrodes corresponding to each nozzle. Each individual electrode is connected to an electrode lead provided on the base of the head drive printed circuit board by a conductive material. A conductive pattern portion is formed on the back surface connection substrate at a position where the back surface of the conductive substrate of the electrode substrate is fixed.

The head body is manufactured by laminating the liquid chamber substrate, the diaphragm substrate, and the electrode substrate, and a head driving printed board is connected to the electrode substrate of the manufactured head body to manufacture a head. The back connection substrate of the head, in which the head body is fixed to the back connection substrate, is fixed to an ink cartridge or another fixing member, and the external connection wiring connected to the back connection substrate is electrically connected to ground, Set the substrate of the board to the ground level.

When printing characters and images using this head, the ink supplied from the ink cartridge passes through the common liquid chamber of the head body and fills the liquid chambers in the entire area of each ink supply channel. In this state, when the individual electrodes of the electrode substrate are individually energized from the head drive printed circuit board according to the image information, an electrostatic force is generated between the individual electrodes and the diaphragm, and the diaphragm is driven by the individual electrodes. Displace to the side. Next, when the energization of the individual electrodes is turned off, the diaphragm attempts to return to the original state. At this time, the sudden change in volume causes the ink to fly from the nozzle as droplets. Since the substrate of the electrode substrate is at the ground level via the back surface connection substrate when the individual electrodes are energized in this way, it is possible to prevent potential from being generated on the individual electrodes that are not driven through the substrate and to drive the electrodes. This prevents cross talk that vibrating plates do not vibrate.

[0021]

FIG. 1 is a perspective view of an ink jet head according to an embodiment of the present invention. As shown in the figure, an ink-jet head (hereinafter, referred to as a head) 1 has a head body 5 in which a liquid chamber substrate 2, a diaphragm substrate 3, and an electrode substrate 4 are laminated by a direct bonding method such as an adhesive or anodic bonding. Electrode substrate 4
Has a back surface connection substrate 6 bonded to the back surface of the substrate with a conductive adhesive. A head drive printed circuit board 7 is connected to the electrodes of the electrode substrate 4, and an external connection wiring 8 is connected to the electrodes of the back surface connection substrate 6.

The liquid chamber substrate 2 is provided with a plurality of nozzles 9 as shown in FIG. As shown in the sectional view of FIG.
And a liquid chamber 11 communicating with the nozzle 9 and a common liquid chamber 12 communicating with each of the liquid chambers 11 are formed by the liquid chamber substrate 2 and the vibration plate 10 of the vibration plate substrate 3. The electrode substrate 4 is made of a conductor or a semiconductor and has conductivity, an insulating layer 14 formed on the substrate 13, and formed on the insulating layer 14. And the individual electrodes 15 corresponding to the respective nozzles 9 are provided to face each other. Each individual electrode 15 is composed of an electrode lead 17 provided on a base 16 of a printed circuit board 7 for driving a head and a connecting member 1 made of a conductive material such as solder or an anisotropic conductive film.
8 are connected.

The liquid chamber substrate 2 is formed with a groove by a known method such as machining such as dicing or electroforming such as etching, and is joined to the diaphragm substrate 3 to form the nozzle 9, the liquid chamber 11 and the common liquid chamber 12. Can be formed. As a material of the liquid chamber substrate 2, a metal such as stainless steel, a semiconductor such as Si, or an insulating material such as glass is used. When a conductive material such as metal or Si is used, it is preferable to connect the liquid chamber substrate 2 to the ground in order to drop the ink inside to the ground level. Nozzle 9
In order to ensure water repellency with the ink on the ejection surface of the surface, a water repellent treatment is performed by a known method such as plating or a water repellent coating.

The diaphragm substrate 3 is made of metal such as stainless steel or S
It is preferable to use a semiconductor such as i. By etching these materials, a fine pattern with a desired thickness can be accurately formed, and the diaphragm substrate 3 itself can be used as a common electrode. When an insulating material such as glass is used, Al, Cu,
A common electrode can be formed by depositing a metal such as Cr, Ni, or Au by vapor deposition or sputtering.

The substrate 13 of the electrode substrate 4 forms a groove having a desired depth by etching a metal such as stainless steel or Si. And resin or SiO ₂
The insulating layer 14 is formed of an insulating material such as
An electrode material such as i, Al, Ti / Pt, or Cu is formed to a desired thickness by a film forming technique such as sputtering, CVD, or evaporation.
Thereafter, an individual electrode 15 is formed in each groove by forming and etching a photoresist. An insulating layer made of SiO ₂ or the like may be formed on the individual electrode 15 in order to prevent the electrode from being damaged by a short circuit or discharge. In addition, by extracting and fixing a part of the common electrode to a region other than the region where the individual electrode 15 is formed on the surface of the electrode substrate 4, the individual electrode 15 and the common electrode can be formed in substantially the same plane. Connection with the driving printed circuit board 7 can be facilitated.

The liquid chamber substrate 2, the diaphragm substrate 3, and the electrode substrate 4 are laminated by a direct bonding method such as an adhesive or anodic bonding to produce a head body 5, and the head body 5 is formed on the electrode substrate 4 of the produced head body 5. The head driving printed circuit board 7 is connected.

As the head driving printed board 7, a plate-shaped printed board made of glass epoxy resin or phenol resin or a film-shaped flexible printed board (FPC) made of polyimide resin or PET resin is used. As a method of electrically connecting the electrode leads 17 of the head driving printed circuit board 7, the individual electrodes 15, and the electrode pads of the common electrode, for example, a method of thermocompression bonding of solder or a method of thermocompression bonding with an anisotropic conductive adhesive And a method of pressing the electrodes together, or a wire bonding method. In the wire bonding method, the electrodes are directly connected by metal wires, so that the connection resistance is low and the reliability is high. The method of thermocompression bonding of solder, the method of thermocompression bonding with an anisotropic conductive adhesive, and the method of press-contacting between electrodes can be performed at the same time because multiple electrodes can be connected at once, making processing easy and low cost. This is an excellent method. Among these, the thermocompression bonding of solder or anisotropic conductive film adheres the substrates after the compression bonding, so there is no need to worry about the connection part being removed in subsequent processing, assembly or printing operation, and it is particularly excellent in terms of reliability. The connection method.

As the connection method, for example, when an anisotropic conductive film is used, the anisotropic conductive film is obtained by dispersing conductive particles called filler in a thermoplastic resin or a thermosetting resin. Heating and pressurizing between the electrodes causes the anisotropic conductive film to be crushed and the filler to come into contact with both electrodes to establish conduction between the electrodes. Using this anisotropic conductive film, for example, as shown in FIG. 4 (a), the anisotropic conductive film 19 is aligned with the end of the electrode lead 17 of the head drive printed circuit board 7, and then temporarily compressed. Then, the anisotropic conductive film 19 is brought into close contact with the head driving printed board 7. Thereafter, as shown in (b), the protective film of the anisotropic conductive film 19 is removed, and the electrode pads at the ends of the individual electrodes 15 of the electrode substrate 4 and the electrode leads 1 of the printed circuit board 7 for driving the head are formed.
Then, as shown in (c), the heated pressure bonding head 20 is pressed against the electrode region from above the head drive printed circuit board 7 to perform thermocompression bonding. In this manner, the electrode leads 17 of the head drive printed board 7 and the individual electrodes 15 of the electrode board 4 can be easily connected.

As shown in the exploded perspective view of FIG. 5, the back surface connecting substrate 6 has a conductive pattern portion 21 at a position where the back surface of the conductive substrate 13 of the electrode substrate 4 is fixed. , Except for at least the pattern portion 21, and is covered with the insulating resin layer 22. A printed wiring board (PWB) made of a glass epoxy resin or a phenol resin, or a flexible FPC made of a polyimide resin, PET, or the like is used as a base material of the back surface connection substrate 6. A pattern portion 21 is generally formed of copper on the base material. The shape of the pattern portion 21 is such that the electrode substrate 4 fixed to the region of the pattern portion 21 is formed.
The shape may be the same as that of the substrate 13, or a pattern such as a linear shape or a circular shape may be used since at least a part of the pattern portion 21 may be in contact with the substrate 13. The pattern portion 21 is provided at a position other than the position where the head body 5 is mounted on the back surface connection substrate 6.
It has an external connection electrode 23 connected to. As a method for connecting the external connection electrode 23 and the external connection wiring 8, connection using a connector, connection using a wire or a pattern of an FPC and solder, or the like is used. Further, the position of the external connection electrode 23 may be set on the back surface of the back connection substrate 6 which is the opposite surface to which the head body 5 is fixed. As the external connection wiring 8, a dedicated wiring may be used, or the head driving printed circuit board 7 may also be used.

As shown in FIG. 5, the head main body 5 to which the head driving printed circuit board 7 is connected is joined onto the pattern portion 21 of the back connection board 6 to which the external connection wiring 8 is connected. The joining of the head body 5 and the back surface connection substrate 6 is performed using a conductive material. As the conductive material, a conductive adhesive 24 is used to electrically connect the pattern portion 21 of the backside connection substrate 6 to the substrate 13 of the electrode substrate 4 of the head body 5, and to connect the backside connection substrate 6 to the head body 5. And fixing can be performed at once, which is preferable in that the processing cost is low. A conductive adhesive 24 is applied to the pattern portion 21 of the back surface connection substrate 6, and the head body 5 is aligned with that portion and then joined. As a method of aligning the head body 5, an alignment mark 25 corresponding to the size of the substrate 13 is formed at the mounting position of the head body 5 on the back surface connection substrate 6 by silk printing or a copper pattern, and the alignment mark is formed. Positioning can be performed very easily and accurately by positioning the substrate 13 so as to be in contact with the position 25. As another method, as shown in FIG. 6, a frame member 26 corresponding to the size of the substrate 13 of the head main body 5 is provided on the back surface connection substrate 6 by bonding or the like. Alternatively, the substrate 13 may be inserted. After that, in order to securely fix, the conductive adhesive 24 is hardened by heating the back connection substrate 6 with the head main body 5 attached to the back connection substrate 6. Thus, the pattern portion 21 of the back surface connection substrate 6 and the substrate 13 of the electrode substrate 4 of the head main body 5 are electrically connected via the conductive adhesive 24. The connection between the pattern portion 21 of the back surface connection substrate 6 and the substrate 13 of the electrode substrate 4 may be any material having conductivity. In addition to the conductive adhesive 24, an anisotropic conductive film or an anisotropic conductive film may be used. A conductive paste or the like can also be used.

The back connection substrate 6 of the head 1 in which the head body 5 is fixed to the back connection substrate 6 is fixed to an ink cartridge or another fixing member, and the external connection wiring 8 connected to the back connection substrate 6 is grounded. , And the substrate 13 of the electrode substrate 4 is set to the ground level.

When printing characters and images using the head 1, an ink supply pipe connected to an ink cartridge is connected to an ink supply port of the head 1. The ink supplied from the ink cartridge passes through the common liquid chamber 12 of the head main body 5 and fills the liquid chambers 11 in all the ink supply channels. In this state, if the individual electrodes 15 of the electrode substrate 4 are individually energized from the head driving printed circuit board 7 in accordance with the image information, an electrostatic force is generated between the individual electrodes 15 and the diaphragm 10, The diaphragm 10 is displaced toward the individual electrode 15. Next, when the power supply to the individual electrode 15 is turned off, the diaphragm 10 attempts to return to the original state. At this time, due to a sudden change in volume, the ink from the nozzle 9 becomes a droplet and flies. Since the substrate 13 of the electrode substrate 4 is at the ground level via the back surface connection substrate 6 when the individual electrode 15 is energized in this way, it is possible to prevent the potential from being generated on the individual electrode 15 not driven through the substrate 13. Therefore, it is possible to prevent the occurrence of crosstalk in which the non-driven diaphragm 10 also vibrates, and it is possible to stably print a high-quality image.

For example, when the driving voltage is 40 V and the pulse width is 15
When the head 1 was driven under the driving conditions of 10 sec and a continuous driving frequency of 10 kHz, a high quality and good printed image could be obtained. Further, as a result of observing the meniscus of the nozzle 9 not driven, there was almost no meniscus vibration, and no occurrence of crosstalk was observed.

In the above embodiment, an example of a so-called edge shooter type head 1 has been described. However, as shown in a sectional view of FIG. 7, the present invention can be similarly applied to a side shooter type head 1a. Similarly to the head 1, the side shooter type head 1a has the individual electrodes 15 formed on the electrode substrate 4, and the diaphragm 10 of the diaphragm substrate 3 facing the individual electrodes 15 is used as a common electrode to give a potential difference between the two. An actuator for bending the diaphragm 10 by force is formed, and the liquid chamber substrate 2 is joined to the diaphragm substrate 3 to form a liquid chamber 11. A through hole 27 is formed in the liquid chamber substrate 2, and a nozzle substrate 28 having a nozzle 9 corresponding to the through hole 27 is joined on the liquid chamber substrate 2. In addition, an ink supply passage 29 penetrating the electrode substrate 4 and the diaphragm substrate 3 is formed in a region other than the individual electrodes 15 of the electrode substrate 4, and the ink supply passage 29 is electrically connected to the common liquid chamber, thereby forming a lower portion of the electrode substrate 4. It is configured so that ink can be supplied from the side. With this configuration, as shown in FIG.
Can be arranged in two rows in a staggered arrangement, and the head area can be effectively used when it is desired to double the nozzle pitch. A through hole 30 is also formed at a position corresponding to the ink supply passage 29 in the back surface connection substrate 6 joined to the substrate 13 of the electrode substrate 4, and the substrate portion of the electrode substrate 4 is formed in the pattern portion 21 of the back surface connection substrate 6. 13. It is desirable that the pattern portion 21 of the back surface connection substrate 6 be formed at an interval from the through hole 30. This is to prevent the pattern portion 21 from being in contact with the ink in the ink supply passage 29 and the through hole 30 to prevent the pattern from being corroded and to prevent the metal material forming the pattern portion 21 from being eluted into the ink. To do that. Further, a convex portion is formed between the through hole 30 and the pattern portion 21 using an insulating material, and the conductive adhesive 2 for joining the substrate 13 and the back surface connection substrate 6 is formed.
It is preferable that 4 does not contact the ink.

In each of the above embodiments, the substrate 6 for the back surface is provided under the head body 5 and the pattern portion 21 of the substrate 6 for the back surface is brought into electrical contact with the substrate 13 of the electrode substrate 4. Has been described as being at the ground level, but the substrate 13 of the electrode substrate 4 has been described.
The substrate 13 may be brought to the ground level by electrically contacting the side surface of the substrate 13 with the pattern portion of the substrate for external connection.

Further, by using the head 1 or the head 1 in a printer, a facsimile, or a copying machine, a high-density and high-quality image can be stably formed.

Further, in each of the above embodiments, the individual electrodes 15 and the common electrode of the electrode substrate 4 were connected to the head driving printed circuit board 7, and the external connection electrodes 23 of the back surface connection substrate 6 were connected to the external connection wiring 8. Although the case has been described, as shown in FIG. 8, a pattern portion 21 connected to the substrate 13 is provided on
When the substrate 13 is mounted on a printer or the like, the substrate 13 may be directly at the ground level by the printed circuit board 7 for driving the head.

[0038]

As described above, according to the present invention, the ink from each nozzle is controlled by the control signal input to the insulating layer formed on the conductive substrate and the individual electrode formed on the insulating layer. The substrate of the inkjet head that draws characters and images by spraying liquid droplets on the recording medium is connected to the ground level, so that when an individual electrode is energized, potential is not generated on the individual electrode that is not driven through the substrate Therefore, it is possible to prevent cross talk in which a diaphragm that is not driven also vibrates.

Further, by joining a ground level connection substrate having a conductive pattern to the substrate with a conductive material, it is not necessary to separately provide a complicated wire or the like, and the processing of the head is facilitated and the cost is reduced. And the handling of the head can be facilitated.

Also, by joining the substrate and the substrate for ground level connection with a conductive adhesive, the substrate and the substrate for ground level connection can be electrically connected and fixed at one time. Processing cost can be reduced.

Further, by providing the substrate alignment means on the substrate for ground level connection, the substrate and the substrate for ground level connection can be accurately positioned and fixed.

Further, by using this ink jet head for a printer, a facsimile or the like, a high quality image can be stably formed.

Further, ink droplets are sprayed from each nozzle onto a recording medium by a control signal input to an insulating layer formed on a substrate having conductivity and individual electrodes formed on the insulating layer to form a character. By connecting at least a part of the substrate directly to the ground level when an inkjet head that draws images or drawing images is attached to a printer, etc., it is possible to prevent crosstalk from occurring with a simple configuration and stabilize high-quality images Can be formed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a front view showing a nozzle row.

FIG. 3 is a cross-sectional view showing the configuration of the embodiment.

FIG. 4 is a process diagram when a head driving printed circuit board is connected to an individual electrode.

FIG. 5 is an exploded perspective view showing a configuration of a back surface connection substrate and a connection state with a head main body.

FIG. 6 is a perspective view showing another configuration of the back surface connection substrate.

FIG. 7 is a cross-sectional view illustrating a configuration of an inkjet head according to a second embodiment.

FIG. 8 is a perspective view of an inkjet head according to a third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Head 2, Liquid chamber board, 3; Vibrating board board, 4; Electrode board, 5; Head main body, 6; Backside connection board, 7; Head drive printed board, 8; External connection wiring, 9; , 10; diaphragm, 11; liquid chamber, 12; common liquid chamber, 1
3; substrate, 14; insulating layer, 15; individual electrode,
21; pattern part.

Claims (6)

[Claims] An ink droplet is sprayed onto a recording medium from each nozzle by a control signal input to an insulating layer formed on a conductive substrate and individual electrodes formed on the insulating layer. An ink jet head for drawing an image or an image, wherein the substrate is connected to a ground level. 2. The ink jet head according to claim 1, wherein a ground level connection substrate having a conductive pattern on said substrate is bonded with a conductive material. 3. The ink jet head according to claim 2, wherein said conductive material is a conductive adhesive. 4. An ink jet head according to claim 2, wherein said substrate for ground level connection is provided with a substrate positioning means. 5. An ink jet recording apparatus comprising the ink jet head according to claim 1. 6. A method in which ink droplets are sprayed onto a recording medium from each nozzle by a control signal input to an insulating layer formed on a substrate having conductivity and individual electrodes formed on the insulating layer. An ink jet recording apparatus characterized in that at least a part of a substrate of an ink jet head for drawing an image or an image is directly connected to a ground level.