JP2001260353A - Ink jet head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable ink jet head and ink jet recorder in which a high image quality is ensured by realizing reduction of crosstalk at a low cost. SOLUTION: The ink jet head comprises a printed wiring board for applying a voltage to individual electrodes, and a flexible printed wiring board being connected with an earth connection electrode provided on the plane of the electrode substrate other than the electrode plane through an electrical connection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet head and an ink jet recording apparatus, and more particularly to an ink jet recording apparatus using an ink jet head having electrodes formed on a silicon substrate.

[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 so-called inkjet recording method, which is capable of high-speed recording and capable of recording on so-called plain paper without requiring a special fixing process, is an extremely powerful method.
Conventionally, various methods have been proposed or already commercialized and put to practical use. Such an ink jet recording method,
Flying small droplets of recording liquid called so-called ink,
Recording is performed by attaching the recording liquid to a recording medium. The recording liquid is roughly classified into several methods according to a method of generating droplets of the recording liquid and a control method for controlling the flight direction of the droplets. Among them, in recent years, as a method capable of achieving high density and high integration using a silicon substrate, there is a technique described in JP-A-4-52214 and a technique described in JP-A-3-293141 as a method of manufacturing the same. This is a recording method in which a voltage is applied between the substrate and the electrode of the diaphragm, and the diaphragm is displaced by electrostatic force to eject ink. As a head forming method, a liquid chamber and a diaphragm are formed by etching a silicon substrate. Is what you do. Also, as a configuration of this inkjet head,
As described in JP-A-6-50601,
By providing a diaphragm in a part of the ink liquid chamber and providing the counter electrode in a direction different from that of the ink liquid chamber, the head is made denser and thinner, and stable driving of the diaphragm is realized. That is, a common electrode is formed on a diaphragm, an individual electrode facing the common electrode is formed on an electrode substrate, and both electrodes are precisely arranged with a minute gap. In addition, by using a substrate such as silicon which is easy to be etched as an electrode substrate, a groove for forming a minute gap,
An individual electrode located at the bottom can be easily formed. Since the silicon substrate is a semiconductor, the individual electrodes are formed on an insulating layer such as SiO ₂ . However, in this case, in addition to the capacitor formed between the individual electrode and the common electrode, a capacitor is formed between the individual electrode and the substrate of the silicon substrate. A potential is also generated in the individual electrode that is not driven through the straight, and a vibration plate that is not driven also vibrates, which causes so-called crosstalk.

Further, Japanese Patent Application Laid-Open Nos. Hei 5-31905, Hei 7-299908, Hei 9-300329 and Hei 7-246706 disclose a bubble jet (registered trademark) recording device, An FPC connection method of the recording apparatus and the like are shown. The above-described bubble jet recording apparatus has also been put into practical use as an ink jet recording apparatus using a silicon substrate. However, in the case of the bubble jet recording apparatus, a heating resistor is formed on the silicon substrate, and the substrate of the silicon substrate is used. And the capacitance generated between them did not cause any particular problem. Further, even when a piezoelectric body was formed on a silicon substrate, there was no problem because the capacitance of the piezoelectric body was much larger than the capacitance between the piezoelectric body and the substrate.

[0004]

However, in the case of an electrostatic ink jet recording apparatus, a potential difference is provided between two electrodes which are opposed to each other with a gap, and the diaphragm is displaced by an electrostatic force generated therebetween. Therefore, the gap between the two electrodes is kept extremely small in terms of reducing the driving voltage. Therefore, the capacitance between the two electrodes is
Several pF to several tens of pF due to formation with a minute gap
Such a small capacitance. On the other hand, since the capacitance itself between the individual electrode and the substrate is the same, a voltage is applied to the individual electrode that is not driven from the driven individual electrode via the substrate, and as a result, the individual electrode is not driven. A potential difference is generated between the individual electrode and the common electrode of the channel, and a crosstalk in which the vibrating plate that is not driven vibrates poses a problem, and the crosstalk degrades the printed image quality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an ink jet head and an ink jet recording apparatus which can reduce crosstalk at low cost, have high reliability, and obtain high image quality. With the goal.

[0006]

In order to solve the above-mentioned problems, a nozzle for discharging ink, a liquid chamber communicating with the nozzle, and a volume in the liquid chamber are changed so that ink is discharged from the nozzle. The inkjet head according to the present invention, which includes a pressure generating unit for discharging and an electrode substrate on which an individual electrode for applying a voltage to the pressure generating unit is formed, applies a voltage for applying a voltage to the individual electrode. And a flexible printed wiring board connected to the ground connection electrode provided on a surface other than the electrode surface of the electrode substrate by electrical connection means. Therefore, crosstalk can be reduced at low cost,
Good reliability and high image quality.

In addition, since the printed wiring board for voltage application and the printed wiring board for grounding are integrally formed, connection by complicated wires is not required, handling is easy, processing is easy, and the printed wiring board is formed. The cost can be reduced because only one sheet is required.

Further, by using a conductive adhesive for the electric connection means, the electric connection and the fixing of the head can be performed at once, and the processing cost is low.

Further, since the electrical connection means is an elastic member having conductivity, for example, a leaf spring, assembly and processing are simple, and production costs and processing costs can be reduced.

[0010] Further, a head fixing member for fixing the ink jet head is provided, and a printed wiring board for voltage application and / or
Alternatively, when the printed wiring board for grounding is fixed to the head fixing member, a load is applied to the connection portion between the head and each printed wiring board due to vibration during a head assembly or a printing operation, and the connection is disconnected. Can be prevented.

Further, since the ground connection electrode is provided on the back surface of the electrode surface of the electrode substrate, it can be applied to heads of all types and sizes.

[0012] The ink jet recording apparatus according to the present invention comprises:
It is characterized by having the above-mentioned inkjet head.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an ink jet head according to the present invention, a voltage is applied to a printed wiring board for applying a voltage to an individual electrode and a ground connection electrode provided on a surface of the electrode substrate other than the electrode surface. And a flexible grounded printed wiring board connected by means of a dynamic connection means.

[0014]

FIG. 1 is a schematic sectional view showing the structure of an ink jet recording apparatus according to the present invention. As shown in FIG. 1, the ink jet recording apparatus 100 includes four ink cartridges 102 each containing ink of each color of cyan C, magenta M, yellow Y, and black BK, and a plurality of nozzles. Ink supply 4
Inkjet heads 103, a carriage 104 on which the ink cartridges 102 and the inkjet heads 103 are mounted, and a paper feed tray 105 for storing recording paper.
a transport roller 108 for transporting the recording paper from the a, 105b or the manual feed table 106 to the printing unit 107; and a discharge roller 110 for discharging the printed recording paper to a discharge tray 109. When printing the image data sent from the host device on the recording paper, the carriage 104 scans the carriage roller 111 while scanning the carriage roller 1.
In 08, ink is ejected from the nozzles of the inkjet head 103 onto the recording paper sent to the printing unit 107 in accordance with image data to record characters and images.

Next, the ink jet recording apparatus 10 shown in FIG.
The ink jet head 1 used for the ink jet head 0 is an external view of the ink jet head according to the first embodiment of another invention, FIG. 2, FIG.
As shown in FIG. 4 which is a cross-sectional view taken along the line B ′, the liquid chamber substrate 11,
A diaphragm board 12, an electrode board 13, a flexible printed wiring board (hereinafter abbreviated as FPC) 14, which is a printed board,
Two rows of staggered nozzles 15, F arranged in a row
The base 16 of the PC 14, the electrode lead 17 of the FPC 14,
The printed pattern 18 of the FPC 14, the individual electrode 19, the diaphragm 20 also serving as a common electrode, the liquid chamber 21, and the electrode lead 17 of the FPC 14 and the individual electrode 19 of the electrode substrate 13 are electrically connected, for example, solder or anisotropic conductive material. It is configured to include a conductive adhesive 22 such as a film. In addition, common liquid chamber 2
A liquid chamber 3 communicates with each liquid chamber 21 and supplies ink. The gap 24 is a gap between the individual electrode 19 and the diaphragm 20. The fluid resistance 25 is the liquid chamber 21 and the common liquid chamber 2
3, and is formed when the liquid chamber substrate 11 and the diaphragm substrate 12 are close to each other. The electrode substrate 13 is made of a conductor or a semiconductor, and has a conductive substrate 26.
And an insulating layer 27 formed thereon. The back surface of the substrate 26 of the electrode substrate 13 is connected via a conductive adhesive 29 to a back surface connection FPC 28 composed of an electrode lead 30 and a printed pattern 31 for wiring. The ink supply port 32 is a supply port that supplies ink from an ink tank (not shown) to the communicating common liquid chamber 23. Further, the liquid chamber 21, the nozzle 15
Are arranged in a staggered arrangement in two rows and the nozzle pitch is doubled, so that a common ink supply port 32 for supplying ink to both can be formed, so that the head area can be used effectively. Note that, for the sake of simplicity, ink supply means to the ink supply port and the like are omitted.

The liquid chamber substrate 11 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 12 so that the nozzle 15 and the liquid chamber 21 are shared. A liquid chamber 23 can be formed. As a material of the liquid chamber substrate 11,
Metals such as stainless steel, semiconductors such as Si, and insulating materials such as glass are used. In addition, as a joining method, a dry film may be used. A nozzle substrate (not shown) is bonded on the liquid chamber substrate 11 with an adhesive. The ejection surface of the nozzle surface is subjected to a water-repellent treatment by a known method (eg, plating or coating with a water-repellent agent) in order to ensure water repellency with the ink.

Further, the diaphragm substrate 12 is formed by etching a metal such as stainless steel or a semiconductor such as Si.
This is preferable because a fine pattern can be formed with a desired thickness with high accuracy and the diaphragm substrate itself can be used as a common electrode. When an insulating material such as glass is used, a common electrode can be formed by depositing a metal such as Al, Cu, Cr, Ni, or Au on the surface by vapor deposition or sputtering. The diaphragm substrate 12 has a concave portion in which the diaphragm 20 is formed on the bottom surface by a known method such as mechanical processing such as partial polishing or electroforming such as etching.

The electrode substrate 13 is formed by etching a metal such as stainless steel or a semiconductor such as Si.
Forming a gap 24 of a desired height, further to the gap 24, an insulating material such as resin or SiO ₂ insulating layer 2
7 is formed. On top of that, Ni, A
1, electrode material such as Ti / Pt, Cu, etc.
An individual electrode can be formed only in the gap by forming a film to a desired thickness by a film forming technique such as VD or vapor deposition, and then forming and etching a photoresist. In addition, on the surface of the electrode substrate 13, by extracting and fixing a part of the above-described common electrode in a region other than the common electrode formation portion, the individual electrode and the common electrode can be formed in substantially the same plane. This facilitates connection with a printed circuit board (printed circuit board for driving the head) described later. The diaphragm substrate 1
2. The electrode substrate 13 is bonded by a direct bonding method such as an adhesive or anodic bonding. Further, on the individual electrode 19, an insulating layer made of SiO ₂ or a resist material may be formed except for a connection portion with a printed board for the purpose of further preventing the electrode from being damaged by short circuit or discharge. .

On the other hand, as the FPC 14 which is a printed board connected to the individual electrodes 19, a plate-shaped printed board made of glass epoxy resin or phenol resin, or a film-shaped FPC made of polyimide resin, PET resin or the like is used. Can be Further, an electrode lead 17 for applying a voltage to the individual electrode 19 is formed on the FPC 14.
Examples of a method of electrically connecting the electrode lead 17 on the FPC 14 to the individual electrode 19 and the electrode pad of the common electrode include a method of thermocompression bonding of solder, a method of thermocompression bonding with an anisotropic conductive adhesive, and a method of bonding between electrodes. And a wire bonding method. The wire bonding method is a highly reliable connection method because the electrodes are directly connected to each other with a metal wire, so that the connection resistance is low. 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 easily at low cost because the connection between multiple electrodes can be performed at once. This is an excellent method in that there is. Furthermore, among these, FPC
In the method of thermocompression bonding of solder and anisotropic conductive film between the substrate 14 and the electrode substrate, the substrates are adhered to each other after the compression, so that the electrical connection and the fixing of the FPC are simultaneously performed, and the processing, assembly, and printing operations are performed. This is an excellent connection method in that a new bonding step for bonding is not required to improve reliability so that a connection portion cannot be removed due to such reasons.

On the other hand, an FPC 28 for connecting the back surface is connected to the back surface of the electrode substrate 13. This connection method uses solder, a conductive film or paste, or the like. Among them, a conductive adhesive film or a conductive paste is preferable in that the electrical connection and the fixing of the head can be performed once and the processing cost is low. This connection place is the electrode substrate 1
3, the function is to connect the substrate 26 of the electrode substrate 13 to the ground. Therefore, the operation may be performed on the side surface of the electrode substrate 13 where the substrate 26 is exposed on the front surface. FPC2 for this backside connection
Reference numeral 8 may be a dedicated wiring or a printed circuit board for driving a head (FPC 13) as shown in FIG. By using both of them, the number of parts can be reduced, and the processing cost for connection can be reduced, so that the cost can be reduced. In the case of dual use, since the surface of the individual electrode or the common electrode and the back surface are on the opposite surface, as an example of the connection, as shown in FIG. A method of connecting or a method of folding and connecting an FPC having a pattern on only one side as shown in FIG. 6 is used. The FPC of the double-sided pattern in FIG.
Since it is about 5 to 6 times more expensive than the single-sided pattern FPC of FIG. 6, a connection method using a single-sided pattern FPC as shown in FIG. 6 is more preferable.

Further, since the common electrode is normally connected to the ground, the pattern of the common electrode and the pattern for connecting the back surface are connected in the FPC as shown in FIG. And the number of terminals of the connector can be reduced when a connector is used, and the size and cost can be reduced. Specifically, FPC is used as a drive printed circuit board,
An anisotropic conductive film was used to connect it to the electrode substrate, and FPC was used as a printed circuit board for backside connection. Anisotropic conductive films (anisotropic conductive films) are made by dispersing conductive particles called fillers in thermoplastic or thermosetting resin, and heating and pressing between electrodes. Then, the anisotropic conductive film is crushed, and the filler comes into contact with both electrodes to establish conduction between the electrodes. As shown in FIG. 8A, first, after positioning is performed on an electrode portion of a printed circuit board such as the FPC 14 so as to be positioned at an end face of the FPC 14, temporary press-bonding is performed so that the FPC 14 and the anisotropic conductive film are electrically conductive. The adhesive 22 is adhered. After that, the protective film of the anisotropic conductive film is removed, and as shown in FIG.
The electrode pads of No. 3 and the electrode leads of the FPC 14 are aligned. Then, the press-bonding head 51 heated as shown in FIG. 8C is pressed against the electrode area to perform thermo-compression bonding.

In the state where the FPC 14 which is a driving printed board is connected to the electrode substrate 13 of the head, the substrate 2 which is the back surface of the electrode substrate 13 of the head is next.
FPC 28 for backside connection using conductive adhesive 29 for 6
Connect. Thus, the substrate 26, which is the back surface of the electrode substrate 13, is connected to the FPC 28 for back surface connection via the conductive adhesive 29. Also, F for the back side connection
The printed pattern 31 of the PC 28 is directly connected to a printed circuit board (not shown) connected to the ground with solder or a conductive adhesive, or connected via a connector. Thus, the substrate 26, which is the back surface of the electrode substrate 13, is at the ground level.

In this manner, the FPC 2 for back surface connection to which the substrate 26 of the electrode substrate 13 of the head is connected.
8 is fixed to the ink cartridge or another fixing member.

Next, the operation of the ink jet head of this embodiment will be described. First, the ink supplied from the ink supply pipe to the ink supply port 32 passes through the common liquid chamber 23 and fills the entire ink supply channel. When the individual electrodes 19 are individually energized according to the image information, an electrostatic force is generated between the individual electrodes 19 and the diaphragm 20, and the diaphragm 20 is displaced toward the individual electrodes 19. Next, when the power is turned off, the diaphragm 20 attempts to return to the original state. Due to the rapid volume change at this time, the ink is
5 and fly as droplets. When the head unit was driven under the driving conditions of, for example, a driving voltage of 40 V and a pulse width of 15 μsec, a good, high-quality printed image was obtained. When the meniscus of the nozzle 15 not driven was observed, almost no meniscus vibration was observed, and no crosstalk was observed.

FIG. 7 is a sectional view showing the structure of an ink jet head according to a second embodiment of the present invention. 4, the same reference numerals as those in FIG. 4 denote the same components. As a different component, a fixing member 52 having conductivity is fixed to the back surface of the head. As the fixing method, a conductive adhesive such as a conductive paste is preferably used. In addition, as a material having conductivity, a metal such as Cu, Ni, or Al, an alloy thereof, or a material in which a metal layer is formed on a surface of an insulating material such as resin, glass, or ceramic is used. An electrode for connecting the back surface of the FPC is connected to this conductive material. After these are connected, it is preferable to seal the entire back surface connection portion with resin or the like from the viewpoint of protecting against mechanical damage such as bending and maintaining reliable connection.

FIG. 9 is a sectional view showing the structure of an ink jet head according to a third embodiment of the present invention. The present embodiment is an example in which a material having conductivity is used as a leaf spring. A part of the leaf spring 53 is in contact with the electrode substrate 13, and an electrode for connecting the back surface of the FPC is fixed at other parts. Even if a conductive adhesive is not used due to the elasticity, the back surface of the electrode substrate 13 and the leaf spring 53 come into contact with each other,
And the back surface of the electrode substrate 13 are electrically connected.

FIG. 10 is a side view showing the structure of an ink jet head according to a fourth embodiment of the present invention. As shown in the figure, the individual electrodes, the common electrode, and the FP
The head to which C is connected is fixed to the fixing member 54 by an adhesive member 55 such as a double-sided adhesive tape. At this time, F
By fixing the PC to the fixing member 54, a force is applied to a connection portion between the head and the FPC due to vibration during a head assembling to the carriage or an actual printing operation.
The problem of disconnection is eliminated.

FIG. 11 is a plan view showing a printed wiring board for connecting the back surface of the electrode substrate. As shown in the drawing, a printed circuit board 28 for back surface connection is formed by FPC, a pattern 31 is formed at a position where the back surface of the electrode is fixed, and an electrode lead 30 connected to this pattern 31 and a head Electrode pads 4 for connection to individual electrodes and common electrodes
The electrode lead 42 connected to 1 is patterned. Also, at least the pattern 31 and the electrode pad 4
Except for 1, it is covered with an insulating resin layer. FP
A conductive adhesive is applied to the pattern 31 of C, so that the back surfaces of the electrode substrates face each other, and the individual electrodes and the common electrodes of the electrode substrates correspond to the electrode pads 41 on the FPC.
After the alignment, the two are joined. The conductive adhesive may be heat-cured to ensure bonding. Thereafter, the individual electrodes, the common electrode, and the corresponding F
The electrode pads of the PC are connected by wire bonding. Thereafter, the wire bonding portion is sealed with a sealant such as a silicone resin or an epoxy resin in order to prevent disconnection of wires or contact between wires due to mechanical contact, and to prevent electrical short circuit due to ink adhesion. At the other end of the FPC, an electrode lead 42 corresponding to an individual electrode and a common electrode is connected to a drive circuit, and an electrode lead 30 corresponding to the pattern 31 is connected to ground via a ground terminal 43.

As described above, the drive signal supply to the individual electrodes and the common electrode and the ground short-circuit on the back surface (substrate) of the electrode substrate are performed by using one FPC.
C cost and its assembly cost can be reduced.

In the above-described embodiment, the example in which the conductive member is fixed to another fixing member has been described. However, the conductive member and the fixing member may be combined. In this case, at least the position of the fixing member to which the head is fixed may be formed of a conductive material, or a layer of a conductive material may be formed by vapor deposition or bonding. Further, in the above-described embodiment, an example in which the pattern of the printed board, or the conductive member and the conductive member are electrically connected and fixed on the back surface of the electrode substrate of the head has been described. For example, the connection may be made by a substrate on the side surface of the electrode substrate. Furthermore, the ink jet head of the above embodiment is a so-called side shooter type head, but need not be limited to this, and it goes without saying that it can be applied to a so-called edge shooter type head. That is, the present invention is not limited to the above embodiment, and needless to say, various modifications and substitutions can be made within the scope of the claims.

[0031]

As described above, a nozzle for discharging ink, a liquid chamber communicating with the nozzle, and a pressure generating means for discharging ink from the nozzle by changing the volume of the liquid chamber. And an electrode substrate on which an individual electrode for applying a voltage to the pressure generating means is provided.The inkjet head according to the present invention includes a voltage applying printed wiring board for applying a voltage to the individual electrode, and an electrode. And a flexible grounded printed wiring board connected by electrical connection means to a ground connection electrode provided on a surface other than the electrode surface of the substrate. Therefore, crosstalk can be reduced at low cost, reliability is high, and high image quality is obtained.

Further, since the printed wiring board for voltage application and the printed wiring board for grounding are integrally formed, the connection by complicated wires is unnecessary, the handling is easy, the processing is easy, and the printed wiring board is easy to be processed. The cost can be reduced because only one sheet is required.

Further, by using a conductive adhesive for the electric connection means, the electric connection and the fixing of the head can be performed at once, and the processing cost is low.

In addition, since the electric connection means is an elastic member having conductivity, for example, a leaf spring, assembly and processing are simple, and production costs and processing costs can be reduced.

Further, a head fixing member for fixing the ink jet head is provided, and a printed wiring board for voltage application and / or
Alternatively, when the printed wiring board for grounding is fixed to the head fixing member, a load is applied to the connection portion between the head and each printed wiring board due to vibration during a head assembly or a printing operation, and the connection is disconnected. Can be prevented.

Further, since the ground connection electrode is provided on the back surface of the electrode surface of the electrode substrate, it can be applied to heads of all types and sizes.

As another invention, the invention can be applied to an ink jet recording apparatus having at least one ink jet head.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of an ink jet recording apparatus of the present invention.

FIG. 2 is an external view of an inkjet head according to a first embodiment of another invention.

FIG. 3 is a view taken in the direction of arrow A in FIG. 1;

FIG. 4 is a sectional view taken along line B-B ′ of FIG. 1;

FIG. 5 is a cross-sectional view illustrating a connection example using an FPC having a pattern on both sides.

FIG. 6 is a cross-sectional view showing a connection example using an FPC having a pattern on one surface.

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

FIG. 8 is a process diagram when a printed circuit board is connected to individual electrodes.

FIG. 9 is a cross-sectional view illustrating a configuration of an inkjet head according to a third embodiment of another invention.

FIG. 10 is a sectional view showing a configuration of an ink jet head according to a fourth embodiment of another invention.

FIG. 11 is a plan view illustrating an example of a printed circuit board.

FIG. 12 is a plan view showing another example of a printed circuit board.

[Explanation of symbols]

11: liquid chamber substrate, 12: diaphragm substrate, 13: electrode substrate,
14, 28: printed circuit board, 15: nozzle, 16: base, 17, 30: electrode lead, 18, 31: printed pattern, 19: individual electrode, 20: diaphragm, 21: liquid chamber,
22, 29: conductive adhesive, 23: common liquid chamber, 24: gap, 25: fluid resistance, 26: substrate, 2
7: insulating layer, 32: ink supply port, 51: pressure bonding head,
52, 54: fixing member, 53: leaf spring, 55: adhesive member.

Claims (8)

[Claims] 1. A nozzle for discharging ink, a liquid chamber communicating with the nozzle, pressure generating means for changing the volume of the liquid chamber to discharge ink from the nozzle, and a pressure generating means. In an ink jet head having an electrode substrate on which an individual electrode for applying a voltage is formed, a printed wiring board for applying a voltage to the individual electrode, and a voltage applying printed wiring board provided on a surface other than the electrode surface of the electrode substrate. And a flexible grounded printed wiring board connected to the ground connection electrode provided by an electrical connection means. 2. The ink jet head according to claim 1, wherein said printed wiring board for voltage application and said printed wiring board for grounding are integrally formed. 3. The ink jet head according to claim 1, wherein the electric connection means is a conductive adhesive. 4. The ink jet head according to claim 1, wherein the electric connection means is an elastic member having conductivity. 5. The ink jet head according to claim 4, wherein said elastic member is a leaf spring. 6. A printed wiring board for voltage application, comprising: a head fixing member for fixing an ink jet head.
The inkjet head according to any one of claims 1 to 5, wherein the printed wiring board for grounding is fixed to the head fixing member. 7. The ink jet head according to claim 1, wherein the ground connection electrode is provided on a back surface of the electrode surface of the electrode substrate. 8. An ink jet recording apparatus comprising the ink jet head according to claim 1.