JPH07299903A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the permeation of ink to a protruding part and the cavitation of ink in the gap formed between the protruding part and a partition wall by efficiently ejecting the ink energized by the vibration of the protruding part by filling the gap with a filler to prevent the ink from entering the gap. CONSTITUTION:An ink jet head has a large number of ink chambers 29... mutually separated by partition walls and arranged in one row. Protruding parts 17a having piezoelectric elements protrude to the interiors of the respective ink chambers 29 and gaps 36 are formed between the side surfaces thereof and the partition walls. A plurality of electrodes 32, 33 are arranged corresponding to each of the piezoelectric elements of the respective protruding parts 17a and the gaps 36 formed between the protruding parts 17a and the partition walls are filled with fillers 36a, 17c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a multi nozzle type ink jet head.

[0002]

2. Description of the Related Art In an ink jet recording apparatus having a multi-nozzle type ink jet head, a plurality of ink chambers are arranged in a line in the ink jet head, and adjacent ink chambers are separated by partition walls. . Then, recording is performed by ejecting ink from each ink chamber onto a printing medium that moves relatively in a direction orthogonal to the arrangement direction.

In the case of an ink jet head which ejects ink in an ink chamber by utilizing the piezoelectric effect, generally, a convex portion having a piezoelectric body is provided in a protruding manner in each ink chamber, and the piezoelectric effect is utilized. Then, the ink in the ink chamber is ejected from the nozzle in a droplet form. FIG. 25 is a cross-sectional view of essential parts showing an example of an inkjet head described in JP-A-62-56150. This inkjet head has a plurality of recesses 5 on one side (the upper side in the drawing).
2 and a plurality of recesses 52.
And a cover plate 54 for covering the plurality of recesses 52, and the plurality of recesses 52 serve as ink chambers. A convex portion 53 is provided on the bottom surface of the concave portion 52. The adjacent ink chambers are separated from each other by the partition wall formed by the piezoelectric plate 51.

The concave portion 52 and the convex portion 53 are formed by providing a wide groove a on the tip end surface of the convex portion 53 and two deep grooves b forming a gap between the side surface of the convex portion 53 and the partition wall. There is. An electrode 55 is provided on the other surface of the piezoelectric plate 51, an electrode 56 is provided on the tip surface of the convex portion 53, and a nozzle hole 57 communicating with the ink chamber is also provided on the piezoelectric plate 51. Has been.

In such an ink jet head, a voltage is applied between the electrodes 55 and 56 to deform the convex portion 53 of the piezoelectric plate 51, thereby changing the volume of the ink chamber, and accordingly, changing the volume of the ink chamber. The ink is ejected from the nozzle hole.

[0006]

However, in such a conventional ink jet head, the ink, which is urged by the vibration of the convex portion having the piezoelectric body, has a gap between both sides of the convex portion (the groove b in FIG. 25). ),
In addition to lowering flight efficiency, the following problems are likely to occur.

That is, the penetration of the ink into the inside of the convex portion from both sides of the convex portion lowers the bulk resistance of the piezoelectric body and causes an effective voltage drop and electrolysis of the ink. Alternatively, there is a problem that the ink in the gaps on both sides of the convex portion causes cavitation due to the vibration of the convex portion and hinders flight. Therefore, in view of the above problems, the present invention is capable of efficiently ejecting ink energized by the vibration of the convex portion having the piezoelectric body, and lowering the effective voltage due to the permeation of the ink into the convex portion and inhibiting the ink ejection due to cavitation. It is an object of the present invention to provide an inkjet recording device that does not cause the above problem.

[0008]

In order to achieve the above object, an ink jet recording apparatus according to the present invention is provided with a plurality of ink chambers arranged in a line and adjacent to each other are separated by partition walls, and each ink chamber. A protrusion that is provided in such a manner that a gap is formed between the side surface and the partition wall and that includes a piezoelectric body, and a plurality of electrodes that are arranged corresponding to the piezoelectric body of each protrusion It is characterized by comprising an inkjet head having a filling material to be filled, an ink supply means for supplying ink to a plurality of ink chambers, and a voltage application means for applying a voltage to a plurality of electrodes.

[0009]

In the ink jet recording apparatus having the above structure,
When the voltage applying means applies a voltage to the plurality of electrodes, the piezoelectric body of the convex portion is deformed (vibrated) by the voltage effect. Ink in the ink chamber is ejected from a predetermined nozzle hole by the vibration of the piezoelectric body. The gap formed between the convex portion and the partition wall is filled with the filler, and this filler absorbs vibrations and prevents the vibration of the convex portion from being directly transmitted to the partition wall.

The filling material filling this gap is
Prevents ink from entering the gap. Therefore, the ink that has been energized by the vibrations goes around into the gap, which reduces the flight effect, causes the ink to permeate the inside of the protrusion from both sides of the protrusion, and causes cavitation in the gap due to the vibration of the protrusion. There is nothing to do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet recording apparatus of the present invention will be specifically described below based on the embodiments shown in the drawings. [Embodiment 1] This embodiment is an example in which the plate portion and the convex portion of the piezoelectric member of the multi-nozzle head are integrally formed of a piezoelectric material.

[Regarding Overall Configuration of Inkjet Recording Apparatus] FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to an embodiment of the present invention. This inkjet recording apparatus is roughly classified into a main body paper feed drive system 1, a main engine controller 2, a controller 3, a cleaning / recovery mechanism 4, an interface 5, a driver unit 6, a line head unit 7, and an operation unit. Part 8 and output tray 9
And a body 10 and a recording paper cassette 11. The line head unit 7 is provided with multi-nozzle heads 13 of four colors of yellow, magenta, cyan, and black along the horizontal sheet passing direction (from left to right in FIG. 1).

The multi-nozzle head 13 is arranged such that the nozzles for ejecting ink are directed downward, and the depth direction of each ink chamber is directed upward. Also, FIG.
Although not shown in the figure, the multi-nozzle head 13 is arranged in the horizontal direction orthogonal to the paper passing direction (front and back direction of the paper surface in FIG. 1).
Has a width, and the ink chambers are arranged along the width direction.

[Construction of Multi-Nozzle Head] FIG. 2 is a schematic plan view of the multi-nozzle head 13, and FIG. 3 is a partial perspective view of the multi-nozzle head 13. As shown in FIGS. 2 and 3, the multi-nozzle head 13 includes a base plate 15 made of alumina, for example.
And the terminal plate 16 attached on the base plate 15.
And a piezoelectric member 17, and a non-piezoelectric member 18 and the like provided on the piezoelectric member 17 (see also FIG. 12). The piezoelectric member 17 is made of PZT piezoelectric ceramic, for example, but various piezoelectric materials described later can be used.

As shown in FIG. 3, the piezoelectric member 17 has a shape in which a large number of convex portions 17a are formed at predetermined intervals in the width direction on a rectangular plate portion 17d, and the piezoelectric member 17 as a whole. Are integrally formed of a piezoelectric material. The non-piezoelectric member 18 is a plate-shaped member made of a material that does not exhibit piezoelectricity (a specific example will be described later), and the surface (the lower surface in FIG. 3) facing the piezoelectric member 17 is Recesses 18a ... Fitting with the protruding portions 17a of the piezoelectric member 17 are formed. The non-piezoelectric member 18 has a depth of, for example, about 2 to 50 mm, and the protrusion 17a of the piezoelectric member 17 has a width of, for example, about 20 to 150 μm. The pitch of the convex portions 17a is, for example, about 42.3 to 2
It is about 54 μm (pixel density: 600 to 100 dpi).

FIG. 4 is a sectional view in the width direction of the main part of the multi-nozzle head 13. As shown in FIG. 4, in the piezoelectric member 17 and the non-piezoelectric member 18, the convex portions 17a ...
It is fitted in the inserted state. Then, the convex portion 17
The ink chamber 29 is provided between the front end surface of a and the bottom surface of the recess 18a.
A space is formed. And the piezoelectric member 1
On the upper surface of each convex portion 17a formed on
Is provided, and the common electrode 33 is provided on the entire surface of the piezoelectric member 17 opposite to the surface on which the convex portions 17a ... Are formed.

An insulating protective film 17c made of a polyimide resin (HL-1110 manufactured by Hitachi Chemical Co., Ltd.) and having a thickness of 10 μm is provided along the surface of the piezoelectric member 17 on the convex portion 17a side (upper side in FIG. 4). . Further, a gap 36 is formed between the side surface of the convex portion 17a and the side surface of the concave portion 18a, and the gap portion 36 and the insulating protection film 17c are formed by a one-component epoxy adhesive (Konishi Co., Ltd.). It is filled with a filling adhesive member 36a made of E30).

FIG. 5 is a sectional view in the depth direction of the main part of the multi-nozzle head 13. A nozzle plate 19 made of, for example, a polyimide film is provided on the front surfaces of the piezoelectric member 17 and the non-piezoelectric member 18. The nozzle plate 19 communicates with the ink chamber 29 and has a tapered nozzle hole. 19a. Nozzle plate 1
9 is adhered to the piezoelectric member 17 and the non-piezoelectric member 18 with an epoxy adhesive. The nozzle hole 19a of the nozzle plate 19 is formed by an excimer laser. The nozzle plate 19 has a thickness of 25 to 200, for example.
A polyimide film (Toray: Kapton) of about μm can be used, and the diameter of the nozzle hole 19a is, for example, 10
It is about 100 μm.

Further, as shown in FIGS. 2 and 3, the non-piezoelectric member 18 is provided with an ink supply slit 35 which communicates with all the ink chambers 29. Then, the ink lid 2 made of an epoxy resin for covering the upper surface of the non-piezoelectric member 18
0 and the closing plate 21 made of epoxy resin that covers both side surfaces of the piezoelectric member 17 and the non-piezoelectric member 18 closes the ink supply slit 35. The ink lid 20 has an ink supply hole 24 for supplying ink to the slit 35.
Is provided.

A large number of terminals 22 are provided on the terminal board 16.
, And a large number of conductors 23 ... Connected to each terminal 22 are integrally formed by metal deposition, and the individual electrodes 32 ... And the common electrode 33 have the conductors 23 and terminals of the terminal plate 16 at the rear end of the protrusion 17a. 22 through the driver unit 6
(See FIG. 1). The polarization direction of the piezoelectric member 17 is determined by the individual electrode 32 and the common electrode 33.
Are arranged so as to be parallel to the direction of the electric field formed by the application of the electric field, and the parallel direction and the ink ejection direction are substantially orthogonal to each other.

The material of the piezoelectric member 17 is shown below.
Such a piezoelectric material can also be used. (1) Piezoelectric crystal: ・ Crystalline (SiO₂) ・ Rochelle salt (RS: NaKC_Four
H_FourO₆・ 4H₂O), ethylenediamine tartrate (ED
T: C₆H₁₄N₂O₆・ Kariu tartrate (DKT: K₂C
_FourH_FourO₆・ 1 / 2H₂O) ・ Secondary ammonium phosphate (A
DP: NH_FourH ₂PO_Four) ・ Perovskite type crystal (e
x. CaTiO₃, BaTiO₃, PLZT) ・ Tang
Stainless bronze crystals (ex. Na_xWO₃ [0.1 <
x <0.28]) ・ Sodium barium niobate (B
a₂NaNb_FiveO₁₅) ・ Potassium niobate (Pb₂K
Nb_FiveO₁₅) ・ Lithium niobate (LiNbO₃) ・
Lithium tantalate (LiTaO₃). In addition, chlorine
Acid soda (NaClO₃) ・ Tourmaline
ne) ・ Sphalerite (ZnS) ・ Lithium sulfate (Li
SO_FourH₂O) -lithium metagallate (LiGaO)
₂) ・ Lithium iodate (LiIO₃) ・ Glycine sulfate
(TGS) -Bismuth germanate (Bi₁₂Ge
O₂₀) ・ Lithium germanate (LiGeO₃)
・ Barium titanate ・ Germanium (Ba₂Ge₂
TiO₈) Etc. (2) Piezoelectric semiconductor: ・ Wurtzite ・ BeO ・ ZnO ・ CdS ・ CdS
e ・ AlN (3) Piezoelectric ceramics: ・ Barium titanate (BaTiO 3)₃) ・ Titaniu
Lead zirconate formate (PbTiO 3₃・ PbZrO₃)
 ・ Lead titanate (PbTiO₃) ・ Burr niobate
Lead umate ((Ba-Pb) Nb₂O₆) (4) Above (1) piezoelectric crystal, (2) piezoelectric semiconductor, (3) piezoelectric ceramic
Powder of mix material is dispersed in plastics and molded
Anything is fine.

[0022] (5) piezoelectric polymer: - polyvinylidene fluoride PVDF (-CH ₂ -CF
₂ −) _n・ Polyvinylidene fluoride / PZT ・ Rubber /
PZT-Copolymer of trifluoroethylene and vinylidene fluoride-Copolymer of vinylidene cyanide and vinyl acetate-Polyvinylidene fluoride, etc.

These piezoelectric materials may be polarized and then processed as a piezoelectric member for use, or may be processed as a piezoelectric member and polarized before use. Further, the non-piezoelectric material that can be used for the non-piezoelectric member 18 includes the following (6) to
There is one listed in (9). (6) Ceramics: Al ₂ O ₃ , SiC, C, BaTiO ₃ , BiO
_{3 · 3SnO 2, Pb (Zr} x, Ti 1-x) O 3, Z
nO ₂ , SiO ₂ , (1-x) Pb (Zr _x , Ti
_1-x ) O ₃ + (x) La ₂ O ₃ , Zn _1-x Mn _x Fe ₂ O ₃
, Γ-Fe ₂ O ₃ , SrO.6Fe ₂ O ₃ , La _1-x C
a _x CrO ₃ , SnO ₂ , transition metal oxide, ZnO-
Bi ₂ O ₃ , semiconducting BaTiO ₃ , β-Al ₂ O ₃ ,
Stabilized zirconia, LaB _6, B ₄ C, _{diamond, TiN, TiC, Si 3 N} 4, Y 2 O 2 S: Eu
, PLZT, ThO ₂ , -CaO.nSiO ₂ ,
Ca ₅ (F, Cl) P ₃ O ₁₂ , TiO ₂ , K ₂ O · nA
l ₂ O ₃ (7) Glasses: Elemental glass = Si, Se, Te, As Hydrogen-bonded glass = HPO ₃ , H ₃ PO ₄ , SiO ₂ ,
_{B 2 O 2, P 2 O} 5, GeO 2, As 2 O 3 oxide glass _{= SbO 3, Bi 2 O 3} , P 2 O 3, V 2
O ₅ , Sb ₂ O ₅ , As ₂ O ₃ , SO ₃ , ZrO ₂ Fluoride glass = BeF ₂ · Chloride glass = ZnCl ₂ Sulfide glass = GeS ₂ , As ₂ S ₃ Carbonate glass = K ₂ CO ₃ , MgCO ₃ nitrates glass _{= NaNO 3, KNO 3, AgNO} 3 sulfate glass _{= Na 2 S 2 O 3 ·} H 2 O, Tl 2 SO
_4, alum silicate glass = SiO ₂ silicate alkali glass _{= Na 2 O-CaO-SiO} 2 potash lime glass _{= K 2 O-CaO-SiO} 2 soda _{= Na 2 O-CaO-SiO} 2 lead glass, barium glass Borosilicate glass (8) Plastics: Saturated polyester resin, polyamide resin, aramid resin, acrylic resin, ethylene-vinyl acetate resin,
Ion-crosslinkable olefin copolymers (ionomers), styrene-butadiene block copolymers, polyacetals, polycarbonates, vinyl chloride-vinyl acetate copolymers, cellulose esters, polyimides, heat-resistant resins such as styrene resins.

Thermosetting resins such as epoxy resin, urethane resin, nylons, silicone resin, phenol resin, melamine resin, xylene resin, alkyd resin and thermosetting acrylic resin. Polyvinylcarbazole, polyvinylpyrene, polyvinylanthracene,
Photoconductive resin such as polyvinyl chloride.

[0025] These may be used alone or in combination. In addition, engineering plastics such as liquid crystal polymer, a mixture of plastics and powder, and whiskers may be used. Photosensitive resin, thick film photoresist resin, etc. can be used. Bakelite, fluorine resin, glass / epoxy resin (glass filler mixed in epoxy) may be used.

(9) Others: When the side surface in contact with the ink chamber is coated with an insulating film, all metals can be used. These non-piezoelectric materials are formed into a plate shape and then processed into the non-piezoelectric member 18, or molded into the shape of the non-piezoelectric member 18 from the beginning by utilizing pattern etching, photocuring or the like. Is also good.

[Regarding Manufacturing Process of Main Part of Multi-Nozzle Head] A manufacturing process of a main part of the multi-nozzle head 13 having the above-described structure will be described with reference to FIGS. First, as shown in FIG. 6, 10 μm to 0.1 μm of Au / Ni film or Au / (Ni, Cr) sputtered film by electroless plating is formed on the upper and lower surfaces of the PZT piezoelectric plate which is the material of the piezoelectric member 17. Then, the electrode layers 32 and 33 are formed.

Next, as shown in FIG. 7, a plurality of convex portions 17a are formed at predetermined intervals using an automatic dicing saw. Thereafter, as shown in FIG. 8, a polyimide resin is applied to the entire surface of the piezoelectric member 17 on the convex portion 17a side by a spin coating method and baked at 180 ° C. for 1 hour to form an insulating protective film 17c.

On the other hand, as the non-piezoelectric member 18, as shown in FIG. 9, for example, a rectangular alumina plate is used.
As shown in 0, the ink supply slit 35 is formed using a dicing saw. Next, as shown in FIG. 11, a concave portion 18a to be the ink chamber 29 is cut on the opposite surface of the ink supply slit 35 in a direction orthogonal to the slit 35 with a dicing saw. (In this case, the convex portion 1 of the piezoelectric member 17
Then, the piezoelectric member 17 is placed on the base plate 15, the piezoelectric member 17 and the non-piezoelectric member 18 are fitted, and the gap portion 36 is epoxy-bonded, as shown in FIG. Fill with the agent and bake at 150 ° C for 30 minutes.

The piezoelectric member 17 is placed on the base plate 15, the piezoelectric member 17 and the non-piezoelectric member 18 are fitted together, and they are bonded with an epoxy adhesive 18b. The nozzle plate 19 with the nozzle hole 19a facing the ink chamber 29 is bonded with an epoxy adhesive. In addition, the ink lid 20 is fixed on the ink supply slit 35, and the closing plates 21 are adhesively fixed to both side surfaces of both members 17 and 18.

In addition, the base plate 15 and the piezoelectric member 17
The non-piezoelectric member 18 can be rationally fixed by integrally fixing the outer surface thereof with a resin molding (not shown). The insulating protection film 17c can also be formed by the methods described in (10) to (14) below.

(10) Application of plastics: saturated polyester resin, polyamide resin, acrylic resin, aramid resin, ethylene-vinyl acetate resin,
Heat-promising resins such as ion-crosslinked olefin copolymers (ionomers), styrene-butadiene block copolymers, polyacetals, polycarbonates, vinyl chloride-vinyl acetate copolymers, cellulose esters, polyimides and styrene resins.

Thermosetting resins such as epoxy resin, phenoxy resin, urethane resin, nylons, silicone resin, fluorosilicone resin, phenol resin, melamine resin, xylene resin, alkyd resin, and thermosetting acrylic resin. Polyvinyl carpazole,
Photoconductive resins such as polyvinyl pyrene, polyvinyl anthracene, and polyvinylol.

These can be used alone or in combination. In addition, engineering plastics such as liquid crystal polymer, a mixture of plastics and powder, and whiskers may be used. Photosensitive resin, thick film photoresist resin, etc. can be used. Bakelite, fluorine resin, glass / epoxy resin (glass filler mixed in epoxy)
But it's okay. These are coating, dipping, spraying, etc.
A known liquid application method may be used.

Among the above, the effects of polyamide resin, aramid resin, epoxy resin, phenoxy resin, fluorosilicone resin, fluororesin, and glass / epoxy resin are particularly excellent. (11) Vapor deposition of oxidation, nitridation, sulfide metal compounds, etc .: Metal oxide compounds (SiO ₂ , SiO, CrO, Al ₂ O _3, etc.),
A metal nitride compound (Si ₃ N ₄ , AlN, etc.), a metal sulfide compound (ZnS, etc.), or an alloy thereof is coated by vacuum deposition, sputtering or the like.

Further, the above plastic (10) may be applied by vapor deposition. Alternatively, parylene resin vapor deposition may be performed. Among the above, the effects of Al ₂ O ₃ and Si ₃ N ₄ are excellent. (12) Hydrocarbon compound coating: Hydrocarbons, oxygen-containing hydrocarbons, sulfur-containing hydrocarbons and other group IV element-containing hydrocarbons, nitrogen-containing hydrocarbons, silicon-containing hydrocarbons, fluorine-containing hydrocarbons and other Halogen-containing hydrocarbon,
Hydrocarbons containing Group III elements are added to P-CVD (plasma CV
D) is applied to form an insulating protective film. Alternatively, they may be applied by P-CVD under a mixed gas phase of them.

Among the above, the effect of the fluorine-containing hydrocarbon is excellent. Note that these films need to be appropriately provided with an undercoat of a-Si (amorphous silicon), a-SiC, a-SiN, or the like according to the compatibility of the adhesiveness with the piezoelectric body. (13) Instead of applying the plastics of (10) above to the surface of the piezoelectric body plate in a coating liquid state, the piezoelectric body forming portion is replaced and impregnated under reduced pressure to form the molded body.

(14) The surface of the piezoelectric plate is surface-treated with an ink repellent solvent. Comparing the insulating protection films formed by the above methods (10) to (14), the following features are observed (however, (12) is undercoating). * Strength: Strong (12), (11)> (10), (13)> (14) Weak * Smoothness: Good (10)>(13)> (12), (11), (14) Bad * Adhesiveness (including vibration resistance): Strong (10), (13)> (11), (12)> (14) Weak * Durability (including ink resistance): Good (10), (13) > (11), (12)> (14) Poor Others, (14) is simple in processing and can be used as post-processing of (10) to (13). In terms of cost, (10) and (13) are particularly inexpensive.

The methods described in (10) to (14) above may be used in appropriate combination depending on the piezoelectric material and ink type. Further, as the filling adhesive member 36a, a member having an action of absorbing vibration as described in the following (15) to (19) can be used in addition to the above epoxy-based filling adhesive. (15) Thermosetting resins such as epoxy resin, phenoxy resin, urethane resin, nylons, silicone resin, fluorosilicone resin, phenol resin, melamine resin, xylene resin, alkyd resin, thermosetting acrylic resin.

Among the above, the effects of epoxy resin, phenoxy resin, and fluorosilicone resin are excellent. (16) Saturated polyester resin, polyamide resin, acrylic resin, aramid resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyacetal, polycarbonate, vinyl chloride-vinyl acetate Thermofusible resins such as copolymers, cellulose esters, polyimides and styrene resins.

Among the above, the effects of aramid resin, polyimide resin, polyamide resin and ethylene-vinyl acetate resin are excellent. (17) Liquid crystal polymer (18) Photosensitive resin, photoresist for thick film (19) Rubber, synthetic rubber The materials listed in (15) to (19) above may be used alone or in combination. And other powders, whiskers,
You may mix and use a glass filler etc.

Comparing the superiority and inferiority of the materials listed in (15) to (19) above, although it is almost the same for (15) to (17), excellent (15) to (17)>(18)> (19) Inferiority can be seen. "Regarding the Operation of the Multi-Nozzle Head of the Present Embodiment" Next, the operation of the multi-nozzle head 13 of the present embodiment will be described.

FIG. 13 is a diagram for explaining the relationship between the pulse waveform of the applied voltage and the displacement state of the piezoelectric body. First, when a pulse voltage is applied between the individual electrode 32 and the common electrode 33 by the driver unit 6 according to the image signal,
As shown in (a), the individual electrode 32 and the common electrode 33
An electric field in the direction of arrow A is formed between and. Piezoelectric member 17
Is polarized in the direction of arrow P, at this time, the convex portion 17a of the piezoelectric member 17 is deformed in the thickness direction vibration mode to be in the state shown by the dotted line. Therefore, the volume of the ink chamber 29 between the tip surface of the convex portion 17a and the bottom surface of the concave portion 18a is reduced, the ink in the ink chamber 29 is pressurized, the ink is ejected from the nozzle hole 19a, and the recording paper (Fig. (Not shown).

When the voltage between the individual electrode 32 and the common electrode 33 becomes zero, the convex portion 17a of the piezoelectric member 17 returns to the solid line state (the tip of the convex portion 17a is flat), and the volume of the ink chamber 29 increases. Therefore, the ink is supplied to the ink chamber 29 through the ink supply slit 35, and the next ink flight is ready. The above operation is sequentially or simultaneously performed for each ink chamber 29 according to the image signal, so that an image for one line is drawn, and this is continued in synchronism with the movement of the recording paper. The corresponding image is drawn on the recording paper.

As described above, the tip end surface of the convex portion 17a vibrates by becoming convex or flat, and the ink jet head 13 of the present embodiment has the piezoelectric member 17 having the convex portion 17a and the non-partition having the partition wall. Since the piezoelectric member 18 is fixed in a fitted state and the convex portion 17a and the partition wall are not integrated, the vibration of the convex portion 17a is hard to be transmitted to the partition wall. Further, since the partition wall of the ink chamber 29 is formed by the non-piezoelectric member 18, even if an electric field goes around the partition wall, the partition wall does not vibrate due to it.

Since the convex portion 17a of the piezoelectric member 17 and the partition wall are separated by the gap portion 36 filled with the filling adhesive member 36a and the insulating protective film 17c, the vibration of the convex portion 17a is caused by the filling adhesive member 36a and the insulating member. The vibration is not absorbed by the protective film 17c and is not directly transmitted to the partition wall. In addition, the gap 3
Since 6 is filled with the filling adhesive member 36a and the insulating protective film 17c, the following effects occur.

It is prevented that the ink pressurized by the displacement of the piezoelectric member flows into the gap portion 36 and the flying effect is deteriorated. In addition, the ink permeates into the piezoelectric member bulk from the gap 36 to reduce the bulk resistance, thereby preventing a decrease in the effective voltage applied to the piezoelectric member. In addition, the convex portion 17a
The vibration of the ink prevents the ink from cavitation in the gap portion 36 to generate bubbles. That is, it is possible to prevent air bubbles from being generated and becoming an air damper to hinder the flight of ink.

Since the filling adhesive member 36a with which the gap 36 is filled can also serve as the insulating protective film 17c, the insulating protective film 17c can be omitted and the number of manufacturing steps can be reduced. In addition, the filling adhesive member 36a of the gap portion 36
Also serves as an adhesive for bonding the piezoelectric member 17 and the non-piezoelectric member 18. Here, the waveform of the pulse signal applied to each individual electrode 32 is shown in (a-1) to (a-7) of FIG.
By changing as shown in, the following results are obtained.

That is, the pulse (a-1) is a general pulse when the pulse is applied to rapidly reduce the volume of the ink chamber 29 and cause the ink to fly. However, with this pulse, when the ink is ejected by the normal operation as shown in FIG. 13a, the convex portion 17a rapidly returns from the dotted line to the solid line state, so that the volume of the ink chamber 29 suddenly increases and bubbles form from the nozzle portion. When mixed, the ink pressure may be absorbed during the next pulse application to prevent flying.

The pulse (a-2) is a pulse that slowly returns to the solid line state in order to prevent the generation of bubbles. That is, in order to prevent a sudden change in volume of the convex portion 17a after the ink has been ejected, the voltage is gradually decreased instead of abruptly lowering the pulse as in (a-1).

(A-3) and (a-4) are the same as (a) above.
-1) and (a-2), which is the reverse method of ejecting ink, in which the ink chamber 29 is once increased and filled with ink, and then rapidly returned to the original state to reduce the volume of the ink chamber 29, This is a method of causing ink to fly. The reason why the rising edge of the pulse is inclined in (a-4) is the above (a-2).
It is similar to the case of.

In (a-5) and (a-6), the sub-pulse is applied after the main pulse. Especially when ink is ejected at a high frequency (high-speed printing), satellite noise is likely to occur. Therefore, (a-5) or (a-6)
As described above, by slightly increasing the ink chamber 29 by the sub-pulse before the satellite is generated, the trailing portion of the ink column is forcibly sucked into the ink chamber 29 to prevent the satellite.

All of (a-1) to (a-6) in FIG. 13 and (e-1) to (g-1) in FIG. 13 described later are driven by applying a voltage to the individual electrode 32 according to image information. 13A-7 is a type in which a DC voltage is applied to the common electrode 33 side and the individual electrode 32 side is grounded in accordance with image information to form an electric field and driven. . According to this method, a simple switching circuit is required for image control, so that the driver IC is simple and the cost is low.

In FIG. 13 (e-1), the bias voltage applied to the individual electrode 32 of the convex portion 17a is always raised by a constant level. Therefore, ink can be ejected by applying a low voltage to this, so that the driver cost can be reduced. 13 (f-1) and (g-1)
In this example, an AC component is added to the pulse waveform corresponding to one-time image information, and it is possible to achieve good ink out.

Particularly in the case of printing a large number of sheets, the conventional pulse causes a shortage of the ink and the ink is scattered, so that inconveniences such as stains and changes in the ink flying direction become conspicuous. ) And (g-1), the image noise can be prevented. [Embodiment 2] This embodiment is an example in which the plate portion of the piezoelectric member is subjected to conductivity treatment, and FIG. 14 is a cross-sectional view of the piezoelectric member 17 of the multi-nozzle head according to the present embodiment in the widthwise direction. The multi-nozzle head of this embodiment is similar to the multi-nozzle head of the eighth embodiment, but the common electrode 3 as shown in FIG.
3 is not provided, the plate portion 17 of the piezoelectric member 17 is provided.
d is conductively treated with Ag.

The piezoelectric member 17 can be manufactured as follows. PZT piezoelectric plate (N-2 made by Tokin
One use (0.5 mm in thickness), after masking one surface (upper side surface in FIG. 14), zirconium powder was mixed with silver paste (NP-4910 manufactured by Noritake Co., Ltd.) on the other surface (lower side surface in FIG. 14). Paste thickness 200μm
And apply heat diffusion in vacuum at about 500 ° C. for 1 hour.
By performing the thermal diffusion process in this manner, the metal is diffused from the surface coated with the paste to the vicinity of 150 μm inside the PZT piezoelectric plate, and almost the entire plate portion 17d is subjected to the conductivity treatment. After that, the temperature is returned to room temperature and the one side (see FIG.
It can be manufactured by forming an Au / Ni.Cr sputtered film on the upper surface of FIG.

The conductive treatment is performed by using Zr, C in addition to Ag.
It can also be formed by vapor deposition of u or the like.
As described above, the plate portion 17d of the piezoelectric member 17 is subjected to the conductive treatment, so that the conductive film becomes the common electrode 33 of the eighth embodiment.
Therefore, the common electrode 33 does not have to be separately provided. Further, since the plate portion 17d is subjected to the conductivity treatment, the voltage gradient is reduced in the plate portion 17d, and the voltage can be effectively applied to the convex portion 17a.

Also in the multi-nozzle head using such a piezoelectric member 17, the convex portion 17a and the partition wall are not integrated as in the first embodiment, and the partition wall is formed by the non-piezoelectric member 18.
The gap 36 is filled with the filling adhesive member 36a and the insulating protective film 17c.
Is satisfied, the same effect as that described in Example 1 is obtained. [Embodiment 3] This embodiment is an example of a piezoelectric member in which a plurality of piezoelectric chips are arranged on a conductive plate, and FIG.
FIG. 6 is a cross-sectional view of the main part width direction of the piezoelectric member 17 of the multi-nozzle head of this embodiment.

The multi-nozzle head of this embodiment is also the first embodiment.
However, the plate portion 17d of the piezoelectric member 17 is made of a conductor plate obtained by coating a Cu plate having a thickness of 3 mm with a conductive paste (NP-4909 manufactured by Noritake Co., Ltd.) by 40 μm. The convex portion 17a is made of PZT.
(H5D made by Sumitomo Metal Co., Ltd., thickness 0.2 mm), and the individual electrodes 32 and the common electrode 33 are Au / Ni layers formed on both surfaces of the convex portion 17a.

16 to 18 show the piezoelectric member 17 of this embodiment.
FIG. 6 is a diagram illustrating a manufacturing process of. The piezoelectric member 17 can be manufactured as follows. As shown in FIG. 16, PZT
The top and bottom surfaces of the plate X1 are plated with Au / Ni and this is
Paste on the Cu plate X via a conductive paste, 1
Heat cure at 50 ° C. for 30 minutes.

Next, as shown in FIG. 17, the concave portion 18a of the non-piezoelectric member 18 is cut by cutting with a dicing saw.
And the individual electrode 32 on the upper surface of the convex portion 17a is formed. Next, as shown in FIG. 18, the piezoelectric member 17 is manufactured by forming a terminal connection portion at the rear end portion of each individual electrode 32 and the common electrode 33.

The plate portion 17d may be made of a conductor such as Al, Au, Ni or the like, instead of the Cu plate. In the multi-nozzle head of this embodiment, the individual electrode 32 is provided on the upper surface of the convex portion 17a and the common electrode 33 is provided on the lower surface, so that the voltage is applied only between the individual electrode 32 and the common electrode 33. Therefore, the electric field does not wrap around to other portions, and the vibration can be efficiently generated, so that the applied voltage can be reduced accordingly. Further, since the portion acting as the piezoelectric body is only the area of the convex portion 17a, it is difficult for the vibration to propagate to the other ink chambers 29, so that there is an effect of suppressing crosstalk.

Further, similarly to the first embodiment, the convex portion 17a and the partition wall are not integrated, the partition wall is formed by the non-piezoelectric member 18, and the gap portion 36 is filled with the filling adhesive member 36a and the insulating protective film 1.
Since it is filled with 7c, the same effect as that described in the first embodiment is obtained. [Embodiment 4] In this embodiment, there is a gap between the plate portion of the piezoelectric member and the convex portion of the non-piezoelectric member, and the gap portion is filled with the filler. FIG. 3 is a cross-sectional view of the main part width direction of the multi-nozzle head of this embodiment.

The multi-nozzle head of this embodiment is the same as the multi-nozzle head of the first embodiment, except for the following points. The piezoelectric member 17 includes a convex portion 17a and a plate portion 17d.
The thickness ratio was 7: 3, and the total thickness was 0.5 mm. Further, the piezoelectric member 17 and the non-piezoelectric member 18 are shallowly fitted, and a gap 39 is formed between the plate portion 17d of the piezoelectric member 17 and the tip end surface of the convex portion of the non-piezoelectric member 18, The gap 39 is filled with the filling adhesive member 39a and the insulating protective film 17c. PZT (N-21 manufactured by Tokin) is used as the material of the piezoelectric member 17, and phenoxy resin (JA-7405 manufactured by 3M) is used for the filling adhesive member 36a and the filling adhesive member 39a.
The insulating protective film 17c is an epoxy resin film (CG-105 (W) tape-like tacky adhesive made by Nichiban, 50 μm thick).
Is used.

In this multi-nozzle head, the piezoelectric member 17 is covered with the insulating protection film 17c at the time of manufacture,
The non-piezoelectric member 18 and the filling adhesive member 36a are fitted in the gap portion 36, and the filling adhesive member 39a is fitted in the gap portion 39.
It can be manufactured through a process of filling and adhering a, and heating at 150 ° C. for 30 minutes to cure the insulating protective film 17c and the filling adhesive member 36a.

In this multi-nozzle head, since it is not necessary to tightly fit the piezoelectric member 17 and the non-piezoelectric member 18, damage to parts during assembly is reduced, yield is improved, and cost is reduced. Also, as in the first embodiment,
The convex portion 17a and the partition wall are not integrated, the partition wall is formed by the non-piezoelectric member 18, and the gap portion 36 is filled with the filling adhesive member 36a.
And the insulating protective film 17c, the first embodiment
The same effect as the contents described in (4) is produced.

In the first embodiment, the filling adhesive member 36
The materials (15) to (19) mentioned as the material of a can also be used as the material of the filling adhesive member 39a. [Fifth Embodiment] This embodiment is the same as the fourth embodiment, but as shown in FIG. 19B, the convex portion 17 of the piezoelectric member 17 is used.
The gap 36 between the side surface of a and the side surface of the concave portion of the non-piezoelectric member 18
Are filled only with the insulating protection film 17c. Therefore, the filling adhesive member 36a is not used.

In the manufacture of this multi-nozzle head, the piezoelectric member 17 is covered with an insulating protective film 17c,
While fitting the non-piezoelectric member 18 shallowly, the gap portion 39 is filled with the filling adhesive member 39a to be adhered,
It can be manufactured through a process of curing the insulating protective film 17c and the filling adhesive member 36a by heating for a minute.

Thus, even if the gap 36 is filled with only the insulating protective film 17c made of the epoxy resin film, the gap 36 is filled with the filling adhesive member 36 as in the first embodiment.
The same effect as in the case of being filled with a and the insulating protection film 17c is produced. [Embodiment 6] In this embodiment, the piezoelectric member of the multi-nozzle head is provided with a plurality of piezoelectric protrusions on a conductor plate.
This is an example in which the gap is filled only with the insulating protective film, and there is also a gap between the plate portion of the piezoelectric member and the convex portion of the non-piezoelectric member, and the gap portion is filled with the filler. The overall configuration of the inkjet recording apparatus of the embodiment is similar to that of the inkjet recording apparatus of the first embodiment.

FIG. 20 is a cross-sectional view of the main part width direction of the multi-nozzle head of this embodiment. This multi-nozzle head is similar to the multi-nozzle head of the first embodiment, except for the following points. Similar to the piezoelectric member 17 of the third embodiment, the piezoelectric member 17 of the present embodiment has the plate portion 17d made of a conductor plate, the protrusions 17a made of PZT, and the individual electrodes 32 and the common electrode 33 made of Au / Ni layers. There are convex parts 17
It is formed on both sides of a. The surface of the piezoelectric member 17 on the convex portion 17a side is covered with an insulating protective film 17c, and the side surface of the convex portion 17a of the piezoelectric member 17 and the non-piezoelectric member 18 are covered.
The gap 36 with the side surface of the concave portion is filled with only the insulating protective film 17c. The insulating protective film 17c is made of a film that absorbs vibration, for example, an aramid resin film (TX-I series manufactured by Toray, thickness 4 μm).

The piezoelectric member 17 and the non-piezoelectric member 18 are
The plate part 17 of the piezoelectric member 17 is fitted slightly.
A gap 39 (about 200 μm) is also formed between d and the tip surface of the convex portion of the non-piezoelectric member 18. The gap 39 is filled with a filling adhesive member 39a made of a one-liquid type silicone resin (KE-3475 made by Shin-Etsu Silicone) and an insulating protective film 17c.

This multi-nozzle head has a piezoelectric member 17
On the other hand, a silicone resin is applied by a bar coater to the extent that the convex portion 17a is buried, the insulating protective film 17c is covered, the non-piezoelectric member 18 is fitted, and it is kept at room temperature (25 ° C.) for 24 hours.
It can be manufactured through a process of standing for a while to cure the silicone resin. As described above, in the present embodiment, the gap 36 is filled only with the insulating protective film 17c made of the aramid resin film.
As described above, the same effect as when the gap 36 is filled with the filling adhesive member 36a and the insulating protective film 17c is produced. Further, the convex portion 17a and the partition wall are not integrated, and the partition wall is formed of the non-piezoelectric member 18, which is also the same as in the first embodiment, and therefore, the same effect as that described in the first embodiment is obtained.

Also in the multi-nozzle head of the present embodiment, as in the case of the fourth embodiment, the damage of the parts during assembly is reduced, so that the yield is improved and the cost is reduced. Further, by covering the piezoelectric member 17 with the insulating protective film 17c and fitting it with the non-piezoelectric member 18, the gap 36 can be easily filled. [Embodiment 7] In this embodiment, the piezoelectric member of the multi-nozzle head is formed by arranging piezoelectric chips in which a plurality of piezoelectric elements are laminated on an insulating plate, and the convex portion of the non-piezoelectric member and the plate portion of the piezoelectric member are formed. This is an example in which there is also a gap between and, and the gap is filled with the filler, and the overall configuration of the inkjet recording apparatus of the present embodiment is similar to that of the inkjet recording apparatus of the first embodiment.

FIG. 21 is a cross-sectional view of the main part width direction of the multi-nozzle head according to this embodiment. This multi-nozzle head is the same as the multi-nozzle head of the fifth embodiment, except that the plate portion 17d of the piezoelectric member 17 is made of an alumina plate, the convex portion 17a is made of a PZT piezoelectric layer, and the electrode layers 32 and 33 made of palladium or the like. It has a multi-layered structure (4 layers in the figure), and the rest of the configuration is the same as the multi-nozzle head of the sixth embodiment.

The convex portion 17a is formed by forming the PZT piezoelectric layer and the electrode layer 3 on the alumina plate by the green sheet method.
2, the electrode layer 33 can be manufactured by forming a multi-layer, forming wirings on the electrode layer 32 and the electrode layer 33, and then cutting to a predetermined size with a dicing saw. Then, a multi-nozzle head can be manufactured by the manufacturing method similar to that of the sixth embodiment by using the piezoelectric member 17 having such a convex portion 17a.

According to the multi-nozzle head of this embodiment,
Since the amount of displacement due to the applied voltage can be increased in proportion to the number of stacked PZT piezoelectric layers, ink can be jetted at a low voltage and the driver cost can be reduced. Further, it also has the same effect as the multi-nozzle head of the sixth embodiment. [Embodiment 8] This embodiment is an example in which a check valve or an opening / closing valve is provided in the ink supply portion of the multi-nozzle head, and the overall configuration of the ink jet recording apparatus of this embodiment is the same as in Embodiment 1.
This is the same as that of the ink jet recording apparatus.

FIG. 22 is a sectional view in the depth direction of the multi-nozzle head of this embodiment, and FIG. 23 is an enlarged view of the ink supply section. This multi-nozzle head is similar to the multi-nozzle head 13 of the first embodiment, but as shown in the figure, a check valve 41 is provided in the ink passage between the ink supply slit 35 and the ink chamber 29.

When a voltage is applied to the convex portion 17a, the ink in the ink chamber 29 is pressurized and the ink is discharged into the nozzle hole 1
Although jetted from the nozzle 9a, the check valve 41 blocks the ink passage between the ink supply slit 35 and the ink chamber 29 by providing the check valve 41, as shown in FIG. Therefore, there is less pressure loss than when there is no check valve,
The ink flying efficiency from the nozzle hole 19a can be improved. In addition, it is possible to reduce the driver voltage by lowering the applied voltage accordingly.

The same applies to an opening / closing valve instead of the check valve. Further, such a check valve and an on-off valve can be similarly applied to the above-mentioned Examples 2 to 7. [Other Matters] Even in the inkjet head as shown in FIG. 25, if the filling adhesive is filled in the two grooves b, the ink pressurized by the displacement of the piezoelectric member will flow into the grooves b. The effect of preventing the flight effect from decreasing, the effect of preventing the effective voltage to the piezoelectric member from decreasing due to the ink penetrating into the bulk of the piezoelectric member from the groove b and decreasing the bulk resistance, and the vibration of the piezoelectric member. The effect of preventing cavitation in the groove b and generation of bubbles can be similarly obtained.

Further, the piezoelectric material, non-piezoelectric material, insulating film material and filling adhesive member shown in the first embodiment can be appropriately used in the above-mentioned whole embodiments. In addition, in each of the above-described embodiments, the example in which the piezoelectric member 17 has a shape in which the convex portions 17a are formed on the rectangular plate portion 17d is shown, but the shape of the piezoelectric member 17 is not limited to this. As long as it has a shape having a plurality of convex portions on a part of the surface, it can be similarly implemented in various shapes.

The shape of the nozzle hole 19a formed in the nozzle plate 19 shown in each of the above embodiments is shown in FIG.
From the shapes shown in (a) to (j), it is possible to selectively use one that is adapted to the ink conditions and the like. In each of the above embodiments, the ink supply slit 35 is provided in the non-piezoelectric member 18,
Ink chamber 29 through ink supply hole 24 of ink lid 20
Although various configurations are well known for supplying ink to the ink chamber 29, it is possible to arbitrarily select, for example, one that is supplied from the side of the closing plate 21 by an ink supply pipe. Is.

[0082]

As described above, in the ink jet recording apparatus of the present invention, in the multi-nozzle head, the gap formed between the convex portion having the piezoelectric body and the partition wall is filled with the filler. Ink is prevented from entering the gap without impairing the action of the gap that prevents the vibration of the convex portion from being directly transmitted to the partition wall.

Since the ink does not enter the gap, the ink urged by the vibration of the convex portion does not flow around the gap and the flying effect is not impaired. Moreover, since the ink does not penetrate into the inside of the convex portion from both sides of the convex portion, the effective voltage is not lowered and the ink is not electrolyzed. Also, ink cavitation does not occur in the gap. Therefore, in the ink jet recording apparatus, the effect of flying the ink is excellent, and the durability of the convex portion having the piezoelectric body of the ink jet head is excellent.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of the multi-nozzle head according to the first embodiment.

FIG. 3 is a partial perspective view of the multi-nozzle head according to the first embodiment.

FIG. 4 is a cross-sectional view in the width direction of a main part of the multi-nozzle head according to the first embodiment.

FIG. 5 is a sectional view in the depth direction of a main part of the multi-nozzle head according to the first embodiment.

FIG. 6 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 7 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 8 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 9 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 10 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 11 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 12 is a diagram illustrating a main part manufacturing process of the multi-nozzle head according to the first embodiment.

FIG. 13 is a diagram illustrating a relationship between a pulse waveform of an applied voltage and a displacement state of a piezoelectric body.

FIG. 14 is a cross-sectional view of a piezoelectric member of a multi-nozzle head according to a second embodiment in a widthwise direction.

FIG. 15 is a sectional view of a piezoelectric member of a multi-nozzle head according to a third embodiment in a widthwise direction.

FIG. 16 is a diagram illustrating a manufacturing process of the piezoelectric member 17 according to the third embodiment.

FIG. 17 is a diagram illustrating a manufacturing process of the piezoelectric member 17 according to the third embodiment.

FIG. 18 is a diagram illustrating a manufacturing process of the piezoelectric member 17 according to the third embodiment.

FIG. 19 is a cross-sectional view of a main part width direction of a multi-nozzle head according to a fourth embodiment.

FIG. 20 is a cross-sectional view of a main part width direction of a multi-nozzle head according to a fifth embodiment.

FIG. 21 is a cross-sectional view of a main part width direction of a multi-nozzle head according to a sixth embodiment.

FIG. 22 is a sectional view in the depth direction of the multi-nozzle head according to the example.

FIG. 23 is an enlarged view of the ink supply unit of FIG. 22.

FIG. 24 is a diagram showing the shape of nozzle holes of a multi-nozzle head according to an embodiment of the present invention.

FIG. 25 is a main-portion cross-sectional view showing an example of a conventional inkjet head.

[Explanation of symbols]

 17 Piezoelectric member 17a Convex part 17c Insulation protection film 18 Non-piezoelectric member 18a Recessed part 19a Nozzle hole 29 Ink chamber 32 Individual electrode 33 Common electrode 36 Gap part 36a Filling adhesive member

Claims (1)

[Claims] 1. A plurality of ink chambers arranged in a line and adjacent to each other are separated by partition walls, and a gap is formed between each of the ink chambers and a side surface of the ink chamber and the partition wall. A convex portion that is provided so as to include the piezoelectric body, and a plurality of electrodes that are arranged corresponding to the piezoelectric body of each convex portion,
An ink jet head having a filling material that fills the gap, an ink supply unit that supplies ink to the plurality of ink chambers, and a voltage application unit that applies a voltage to the plurality of electrodes. Inkjet recording device.