JP3314313B2 - Inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-nozzle type ink jet recording apparatus in which an ink chamber is formed between a piezoelectric member having a plurality of convex portions and a non-piezoelectric member having a concave portion fitted with the convex portions. About.

[0002]

2. Description of the Related Art As an example of a conventional ink jet recording apparatus, as shown in FIG.
A concave portion 52 is formed in one of the insides, and a convex portion 53 is protruded from the bottom surface of the concave portion 52 to form one wide groove a and two deep grooves b.
Is formed, and then a cover plate 54 is attached to one surface of the piezoelectric plate 51 to thereby form the recess 52.
Are formed as ink chambers, and electrodes 55 and 56 are provided on the other surface of the piezoelectric plate 51 and the tip end surface of the convex portion 53, and a voltage is applied between the electrodes 55 and 56 to form a piezoelectric plate. There is a configuration in which the convex portion 53 of the 51 is deformed to eject ink from the nozzle hole. (See U.S. Pat. Nos. 4,819,614 and 4,752,788)

[0003]

However, in the above-described conventional device, as shown in FIG. 31, it is necessary to form a groove having a complicated sectional shape inside the piezoelectric plate 51, and the manufacturing cost is unnecessarily high. In addition, especially when the density is increased, the width of the two grooves b becomes several μm, so that there is a problem that the processing is substantially difficult.

Further, since the partition forming the ink chamber is formed of a piezoelectric member, the electric field between the two electrodes 55 and 56 wraps around and vibrates the partition to displace the volume of the adjacent ink chamber. There are also problems such as crosstalk caused by flying the ink, and contamination of the periphery of the nozzle, which causes the ink flying direction to fluctuate. Further, even if the wraparound of the electric field can be reduced, the partitioning portion integrally formed with the convex portion 53 is inadvertently deformed to the lateral side with the displacement of the convex portion 53, so that the correct ink can be obtained. Hinder flight,
There is a problem that high-speed response is lacking.

The present invention is proposed in view of the above-mentioned problems, and has as its object the purpose of which is to manufacture an ink-jet printer which can be manufactured more easily than conventional ones, and which can eject ink with little crosstalk while reducing its cost. A recording device is provided.

[0006]

In order to achieve the above object, an ink jet head according to the present invention has a plurality of convex portions having an upper surface and side surfaces coated with an insulating coating,
A piezoelectric member having at least a part of the protrusions as a piezoelectric body, and a non-piezoelectric member made of a non-piezoelectric body having a plurality of concave portions fitted to each of the plurality of protrusions in the piezoelectric member,
An ink jet head having a configuration in which an ink chamber is formed between a front end surface of each of the convex portions and a bottom surface of each of the concave portions facing each other, wherein a bottom surface of each of the concave portions formed between each of the convex portions of the piezoelectric member, The bottom surface and the tip surface of each convex portion formed between each concave portion of the non-piezoelectric member are in contact with each other, and the piezoelectric member and the non-piezoelectric member do not move in the direction in which each contact surface separates. A gap is formed between the side surface of each convex portion of the piezoelectric member and the side surface of each concave portion of the non-piezoelectric member that faces the side surface of each convex portion.

[0007] The insulating coating may be formed of a film containing amorphous carbon.

[0008]

According to the ink jet head of the present invention, the plurality of protrusions of the piezoelectric member and the corresponding plurality of recesses of the non-piezoelectric member are fitted to each other, and the gap between the tip surface of each protrusion and the bottom surface of each recess is formed. This forms an ink chamber. When the pressure is instantaneously applied to the ink chamber, even if the internal pressure of the ink chamber rises instantaneously, the displacement of the non-piezoelectric member due to the pressure can be suppressed. Is ejected from the nozzle hole, and good image quality can be obtained. Further, a gap is formed between the side surface of each convex portion of the piezoelectric member and the side surface of each concave portion of the non-piezoelectric member, so that the deformation of each convex portion of the piezoelectric member can be quickly performed without being restricted by the non-piezoelectric member. In addition, the discharge is sufficiently performed, and the discharge efficiency is improved. Since the insulating coating is applied to the upper surface and the side surface of each projection of the piezoelectric member, it is possible to use a low-resistance ink.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing one embodiment of an ink jet recording apparatus. The inkjet recording apparatus is roughly divided into a main body, a paper feed drive system 1, a main engine controller 2, a controller 3, a cleaning and recovery mechanism 4, an interface 5, a driver unit 6, a line head unit 7, The line head unit 7 includes an operation unit 8, a paper discharge tray 9, a body 10, and a recording paper cassette 11, and has a multi-nozzle head of four colors of yellow, magenta, cyan, and black. 13 is provided.

The multi-nozzle head 13 is provided with a terminal plate 16 made of, for example, alumina on a base plate 15 made of, for example, alumina as shown in plan view in FIG.
As shown in FIG. 1, a piezoelectric member 17 having a convex portion 17a made of, for example, PZT piezoelectric ceramics is provided, and a concave portion 18 fitted with the convex portion 17a is provided on the piezoelectric member 17.
A non-piezoelectric member 18 having a is provided.

Incidentally, it is not possible to use the piezoelectric member of the present invention.
The following piezoelectric materials can be used. Piezoelectric crystals and
For example, quartz SiO_Two・ Rochelle salt (NaKC)_FourH_Four
O₆・ 4H _TwoO), ethylenediamine tartrate (ED
T. C₆H₁₄N_TwoO₆), Potassium tartrate (DKT.K)
_TwoC_FourH_FourO₆・ 1/2 H_TwoO), Ammonium diphosphate
(ADP: NH_FourH_TwoPO_Four), Perovskite connection
CaTiO as a crystal_Three, BaTiO_Three, PLZT, tongue
NaxWO as Gusten bronze crystal_Three, Niobate
Barium sodium (Ba_TwoNaNb_FiveO_Fifteen),niobium
Potassium lead (Pb_TwoKNb_FiveO_Fifteen), Lithium niobate
(LiNbO_Three), Lithium tantalate (LiTaO)
_Three). Further, sodium chlorate (NaCl1)_Three), Tourmaline,
Sphalerite (ZnS), Lithium sulfate (LiSO_FourH
_TwoO), lithium metagallate (LiGaO _Two), Yo
Lithium oxalate (LiIO_Three), Glycine sulfate (TG
S), bismuth germanate (Bi₁₂GeO₂₀) 、 Ge
Lithium rumanate (LiGeO_Three), Titanium acid
Barium germanium (Ba_TwoGe_TwoTiO₈)
Crystal and piezoelectric semiconductors include wurtzite BeO, ZnO,
CdS, CdSe, AlN. As piezoelectric ceramics
Is a barium titanate (BaTiO_Three), Titaniu
Lead zirconate oxalate (PbTiO_Three・ PbZr
O_Three), Lead titanate (PbTiO _Three), Ba niobate
Lead silicate ((Ba-Pb) Nb_TwoO₆).

Alternatively, a powder obtained by dispersing the powder of the above-mentioned piezoelectric crystal, piezoelectric semiconductor, or piezoelectric ceramic material in a plastic may be used. Examples of the piezoelectric polymer include polyvinylidene fluoride PVDF (-CH ₂ -CF _2- ) _n · polyvinylidene fluoride / PZT · rubber / PZT · copolymer of trifluoroethylene and vinylidene fluoride · vinylidene cyanide and vinyl acetate And polyvinylidene polyisocyanate.

After these are polarized, they are used as piezoelectric members.
Processing and use, or processing as a piezoelectric member and polarization
It may be used after processing. Also used as a non-piezoelectric member
Materials that can be used include: Ceramics
As Al_TwoO_Three, SiC, C, BaTiO_Three, BiO
_Three・ 3SnO_Two, Pb (Zr_X, Ti_1-x) O_Three, Zn
O, SiO_Two, (1-x) Pb (Zr_x, Ti_1-x) O
_Three+ (X) La_TwoO_Three, Zn_1-xMn_xFe_TwoO_Three, Γ
-Fe_TwoO_Three, SrO.6Fe_TwoO_Three, La_1-xCa_x
CrO_Three, SnO_Two, Transition metal oxide, ZnO-Bi_Two
O_Three, Semiconductive BaTiO_Three, Β-Al_TwoO_Three, Stabilization
Luconia, LaB₆, B_FourC, diamond, TiN,
TiC, Si_ThreeN_Four, Y_TwoO_TwoS: Eu, PLZT, T
hO_Two, -CaO.nSiO_Two, Ca_Five(F, Cl) P
_ThreeO₁₂, TiO_Two, K_TwoO ・ nAl_TwoO_Three, Glass and
Element glass = Si, Se, Te, As, hydrogen bonding gas
Lass = HPO_Three, H_ThreePO_Four, SiO_Two, B_TwoO_Two, P
_TwoO_Five, GeO_Two, As_TwoO_Three・ Oxide glass = SbO
_Three, Bi_TwoO_Three, P_TwoO_Three, V_TwoO_Five, Sb_TwoO_Five, A
s_TwoO_Three, SO_Three, ZrO_Two・ Fluoride glass = BeF
_Two・ Chloride glass = ZnCl _Two・ Sulphide glass = GeS
_Two, As_TwoS_Three, Carbonate glass = K_TwoCO_Three, MgCO
_Three・ Nitrate glass = NaNO_Three, KNO_Three, AgNO_Three
・ Sulfate glass = Na _TwoS_TwoO_Three・ H_TwoO, Tl_TwoSO
_Four, Alum, silicate glass = SiO_2,Alkali silicate
Rigarasu = Na_TwoO-CaO-SiO_2,Potash lime glass
S = K_TwoO-CaO-SiO_Two, Soda-lime glass = N
a_Twol-CaO-SiO_2,Lead glass_,Barium glass
Borosilicate glass.

As plastics, saturated polyester resin, polyamide resin, acrylic resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyacetal, polycarbonate, vinyl chloride-vinyl acetate Heat-sensitive resin such as copolymer, cellulose ester, polyimide, styrene resin, etc .; heat of epoxy resin, urethane resin, nylons, silicone resin, phenol resin, melamine resin, xylene resin, alkyd resin, thermosetting acrylic resin, etc. Curable resin; a photoconductive resin such as polyvinylcarbazole, polyvinylpyrene, polyvinylanthracene, and polyvinylol, which can be used alone or in combination.

[0015] Other plastics such as liquid crystal polymers. A mixture of plastics, powder and whiskers may be used. Photosensitive resin, photoresist resin for thick film, etc. can be used. When bakelite / fluorinated resin, glass / epoxy resin (glass filler mixed in epoxy) and the side surface in contact with the ink chamber is coated with an insulating film, all metals can be used.

These materials are formed into a plate shape and then processed as a non-piezoelectric member, or molded into a non-piezoelectric member shape from the beginning by using pattern etching, light curing, or the like. May be. A nozzle plate 19 having a nozzle hole 19a made of, for example, a polyimide film is provided on the front surface of the piezoelectric member 17 and the non-piezoelectric member 18.
However, an ink lid 20 made of epoxy resin is provided on the upper surface of the non-piezoelectric member 18, and closing plates 21 made of epoxy resin are provided on both side surfaces of the piezoelectric member 17 and the non-piezoelectric member 18. .

The ink lid 20 has an ink supply hole 2.
4 are provided. Many terminals 22 are provided on the terminal plate 16,
Many conductors 23 connected to each terminal 22 are integrally formed by metal evaporation. As shown in FIGS. 4 and 5, a large number of convex portions 17a are formed at predetermined intervals in the width direction along the depth direction at portions other than the rear end portion of the piezoelectric member 17, and each convex portion 17a The non-piezoelectric member 18 is fitted in a concave portion 18a.

The piezoelectric member 17 and the non-piezoelectric member 18 are
For example, only the two end portions of the non-piezoelectric member 18 are adhered to each other by an epoxy-based adhesive, and a space forming the ink chamber 29 is formed between the tip end surface of the convex portion 17a and the bottom surface of the concave portion 18a. I have. The nozzle plate 19 is bonded to the piezoelectric member 17 and the non-piezoelectric member 18 with an epoxy-based adhesive, and the nozzle plate 19 has a tapered nozzle hole 19a communicating with the ink chamber 29 formed by an excimer laser. It is formed for each ink chamber 29.

An individual electrode 32 is provided on the upper surface of each projection 17a of the piezoelectric member 17, and a common electrode 33 is provided on the opposite surface. That is, the direction of polarization of the piezoelectric member 17 is parallel to the direction of the electric field formed on the individual electrode 32 and the common electrode 33, and the parallel direction intersects the ink ejection direction. The individual electrode 32 and the common electrode 33 are connected to the output end of the driver unit 6 shown in FIG. 1 via the conductor 23 and the terminal 22 of the terminal plate 16 at the rear end of the projection 17a. The non-piezoelectric member 18 has an ink supply slit 35 communicating with all the ink chambers 29. The ink supply slit 35 is covered by the ink lid 20 and the closing plate 21 shown in FIG.

The nozzle plate 19 has a thickness of, for example, 2 mm.
A polyimide film of about 5 to 200 μm (Toray: Kapton) can be used, and the diameter of the nozzle hole 19a is, for example, about 10 to 100 μm. The depth of the non-piezoelectric member 18 is, for example, about 2 to 50 mm, and the width of the protrusion 17 a in the piezoelectric member 17 is, for example, about 20 to 150 μm. The pitch of the projections 17a is, for example, about 42.3 to 2
It is about 54 μm (pixel density: 600 to 100 dpi).

The manufacturing process of the main part of the multi-nozzle head 13 will be described with reference to FIGS. First, as shown in FIG. 6, an Au / Ni film formed by electroless plating on the upper and lower surfaces of a PZT piezoelectric plate serving as a piezoelectric member 17,
Alternatively, the AU / (Ni ₁ Cr) sputtered film is
The electrode layers 32 and 33 are formed to a thickness of 0.1 μm.

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, an insulating protective film 17 made of amorphous carbon is formed on the upper surface and side surfaces of the convex portion 17a.
c is formed to 0.5 μm. As a result, ink having low resistance can be used. On the other hand, in the non-piezoelectric member 18, as shown in FIG. 9, an ink supply slit 35 is formed on one surface of an unpolarized PZT plate of, for example, a rectangular alumina plate using a dicing saw as shown in FIG.

Next, as shown in FIG. 11, a concave portion 18a serving as an ink chamber 29 orthogonal to the slit 35 is cut by a dicing saw on the surface opposite to the ink supply slit 35. (In this case, the piezoelectric member 17 is formed to have a size that can be fitted to the convex portion 17a of the piezoelectric member 17.) Then, as shown in FIG. Recess 18 of member 18
a, and an ink chamber 29 is formed between the two portions 17a and 18a.

Then, as shown in FIG.
7, and an epoxy adhesive 1 on the front surface of the non-piezoelectric member 18.
8b, the nozzle plate 19 having the nozzle hole 19a facing the ink chamber 29 is adhered to the ink supply slit 35.
The ink cover 20 is fixed thereon, and the two members 17,
The closing plates 21 are bonded and fixed to both side surfaces of 18. Next, the operation of the embodiment constructed as described above will be described.

First, the driver unit 6 according to the image signal
When a pulse voltage is applied between the individual electrode 32 and the common electrode 33, the individual electrode 32 and the common electrode 3 as shown in FIG.
An electric field in the direction of arrow A is formed between the three. At this time, since the piezoelectric member 17 is polarized in the direction of the arrow P, the convex portion 17a of the piezoelectric member 17 is deformed in the thickness direction vibration mode to be in a state shown by a dotted line. Accordingly, the volume of the ink chamber 29 between the front end surface of the convex portion 17a and the bottom surface of the concave portion 18a is reduced, and the ink in the ink chamber 29 is pressurized, the ink is ejected from the nozzle hole 19a, and the recording paper (shown in FIG. ). At this time, the surface of the convex portion 17a becomes convex as shown by a dotted line, but since the entire piezoelectric member 17 is fitted to the non-piezoelectric member 18 via a gap, the deformation due to the vibration is absorbed, and the vibration is absorbed. It serves not to tell other ink chambers.

When the voltage between the individual electrode 32 and the common electrode 33 becomes zero, the projection 17a of the piezoelectric member 17 returns to the solid line state, and the volume of the ink chamber 29 increases. The ink is supplied to the chamber 29 to prepare for the next ink flight. The above operation is performed sequentially or simultaneously for each ink chamber 29 in accordance with the image signal, so that an image for one line is drawn, and this is continued in synchronization with the movement of the recording paper. The corresponding image is drawn on the recording paper.

In this case, by changing the waveform of the pulse signal applied to each individual electrode 32 from FIG. 13a-1 to FIG. 13a-7, the following results can be obtained and used effectively. In other words, when a pulse is applied to rapidly reduce the volume of the ink chamber 29 and cause ink to fly, FIG.
Are general pulses. However, with this pulse, when the ink is caused to fly by normal operation as shown in FIG. 13A, the piezo convex portion 17a suddenly returns from the dotted line to the solid line state, so that the volume of the ink chamber 29 sharply increases and bubbles are generated from the nozzle portion. When the next pulse is applied, the ink may absorb the ink pressure and prevent flying. The pulse in FIG. 13A-2 is a pulse that slowly returns to the solid line state in order to prevent this bubble generation.

That is, in order to prevent a sudden change in the volume of the convex portion 17a after the ink has jumped, the voltage is gradually decreased instead of sharply dropping the pulse as shown in FIG. 13A-1. FIGS. 13a-3 and 13a-4 show a method of ejecting ink by increasing the ink chamber 29 once, filling it with ink, and then returning the ink chamber 29 sharply, reducing the volume of the ink chamber 29 and ejecting ink. is there. The reason why the rising of the pulse is inclined in FIG.
Same as 3.

FIGS. 13A-5 and 13A-6 show a method of applying a sub-pulse after a main pulse. In particular, when performing ink flying at a high frequency (high-speed printing), satellite noise is likely to occur. FIG. 13A-5 or FIG.
Before the satellite is generated as shown in FIG.
Is slightly increased by the sub-pulse to force the tail of the ink column to be sucked into the ink chamber 29 to prevent satellites.

13a-1 to 13a-6 and FIGS. 13e-1 to 13g-1 which will be described later are of the type in which a voltage is applied to the individual electrode 32 in accordance with image information and driven. Reference numeral -7 denotes a type in which a DC voltage is applied to the common electrode 33 and the individual electrode 32 is grounded according to image information to form an electric field and drive. According to this method, image control can be performed by a simple switching circuit, so that the driver IC is simple and the cost is low.

FIG. 13e-1 constantly shows the bias voltage applied to the individual electrode 32 of the piezo convex portion 17a. Therefore, the ink can be ejected at a low voltage, and the driver cost can be reduced. 13f-1 and 13g
A value of -1 makes it possible to make the ink run out well by adding an AC-like component to a pulse waveform corresponding to one image information.

In particular, in the case of printing a large number of sheets, the conventional pulse does not cut the ink well, so that the ink splatters, and inconveniences such as stains and changes in the ink flying direction become noticeable. Image noise can be prevented by using the waveform of FIG. 13g-1.
Further, as a modified example of the above-described embodiment, as shown in FIGS. 14 and 15, the piezoelectric member 17 and the non-piezoelectric member 18 are configured to be fitted with no gap near the front surface of the multi-nozzle head 13, and A small groove 31 'may be formed to form a nozzle hole. In addition, a small groove 31 may be formed in the convex portion 17a of the piezoelectric member to form a nozzle hole. In this case, the nozzle plate 19 shown in FIGS.

Further, as shown in FIG. 16, the distal end surface of the convex portion 17a of the piezoelectric member 17 and the bottom surface of the concave portion 18a of the non-piezoelectric member 18 may be formed as concave surfaces. In this case, generation of bubbles can be suppressed. Therefore, the ink flying efficiency is improved and the drive voltage can be reduced. As a second embodiment, as shown in FIG. 17, the projections 17a of the piezoelectric member 17 are formed in a laminated shape, and the individual electrodes 32 are formed on the upper surface and the common electrodes 33 are formed on the lower surface.
May be provided.

In this case, since the portion acting as the piezoelectric body is only the upper region of the convex surface 17a, the vibration due to the applied voltage is not easily transmitted to the other ink chambers 29, and the crosstalk can be eliminated. As shown in FIGS. 18 to 20, the manufacturing process of this embodiment is such that the electrodes 32 are formed on the upper and lower surfaces of the insulating rigid plate X.
33, a PZT thin-layer plate X1 formed by a green sheet method is adhered via a conductive adhesive layer, cut with a dicing saw, and the convex portion 1 fitted to the concave portion 18a of the non-piezoelectric member 18 is formed.
7a is formed, and the individual electrode 32 is formed on the upper surface of the projection 17a.

Further, as a modified example of this embodiment, as shown in FIG. 21, for example, a coating liquid obtained by dispersing a PZT piezoelectric powder in a solvent on an alumina plate X2 is screen-printed, pattern-applied, and baked to form a piezoelectric projection 17a. In addition, as the non-piezoelectric member 18, a thick film photoresist may be etched on the plate X3 by pattern exposure to form a partition X4 to form the ink chamber 29. In this case, a cutting process using a dicing saw Can be omitted, so that the cost can be reduced accordingly. Further, as a third embodiment, as shown in FIG. 22, a projection 17a may be provided on an alumina plate X2 in which a PZT piezoelectric layer and an electrode layer formed by a green sheet method are multilayered.

In this case, the amount of displacement due to the applied voltage can be increased in proportion to the number of layers. 17 to 2
The common electrode 33 of the embodiment shown in FIG. 1 is provided on the lower surface of the individual electrode 32 in a one-to-one correspondence in a comb shape and is shared in one place outside the region where the ink chamber 29 is formed. A voltage is applied only between the common electrode 32 and the common electrode 33, and the electric field can be effectively prevented from wrapping around the other portions, thereby effectively generating vibration.

As a fourth embodiment, the projection 17a of the piezoelectric member 17 may be trapezoidal as shown in FIG. 23 as shown in FIG. 23. In this case, the non-piezoelectric member 18 can be easily fitted. Easy assembly. Further, as a fifth embodiment, as shown in FIG. 24, a PZT powder is molded by firing, and thereafter, a silver palladium paste or a palladium paste is applied by printing and baking to form the electrode 32, thereby forming the piezoelectric member 17. The non-piezoelectric member 18 may be formed by injection molding a resin (industrial plastic) material.
In this case, R can be easily formed at the corner of the concave portion 18a, the contact area with the valley of the piezoelectric member 17 is reduced, and it is possible to advantageously cope with the eccentric fitting of the two members 17, 18 on the other hand. By the action of R, the generation of bubbles in the ink chamber 29 can be suppressed.

Further, as a sixth embodiment, as shown in FIG. 25, the convex portions 17a of the piezoelectric member 17 and the concave portions 18a of the non-piezoelectric member 18 may be opposed to each other in a zigzag pattern as shown in FIG. In this case, the strength of the partition wall of the non-piezoelectric member 18 can be increased while the amount of the ink chamber 29 can be increased, and the interval between the rods can be reduced. Further, as shown in FIG. 26, as shown in FIG. 26, the protrusions 17a of the piezoelectric members 17 provided vertically are alternately arranged to face each other, and a resin material having a recess 18a fitted to the protrusions 17a is formed. The non-piezoelectric member 18 may be provided in a sandwich shape so that the ink chambers 29 are arranged side by side. In this case, the non-piezoelectric member 18 is made of a resin, and the partition of the ink chamber 29 is formed by a protrusion of the piezoelectric member 17. Part 1
7a, the ink chambers 29 adjacent to the
Does not affect displacement.

As an embodiment for fixing the fitted state between the piezoelectric member 17 and the non-piezoelectric member 18, as shown in FIG. In this case, the fixing means can be rationalized and the cost can be reduced. Further, as shown in FIG. 28, a panel heater H made of a ceramic heater is provided on the lower surface of the multi-nozzle head 13 so that the surface tension and the viscosity of the ink are always kept constant without being affected by the temperature of the outside air. And stable ink flying can be obtained.

The shape of the nozzle holes 19a formed in the nozzle plate 19 used in each of the above embodiments may be selectively selected from those shown in FIGS. . As an example of a means for fixing the fitted state between the piezoelectric member 17 and the non-piezoelectric member 18 without bonding, as shown in FIG. The support 15a is mounted on the plate 15, and the support 15a is
The arm 15b is provided so as to be freely movable up and down so that one end of the arm 15b abuts on the upper surface of the non-piezoelectric member 18, and the lower surface of the other end of the arm 15b and the base plate 1
5 and an upper surface of the compression machine 15c.
The non-piezoelectric member 18 can be pressed and fixed to the piezoelectric member 17 via the arm 15b with the extension biasing force of 5c.

In this case, the compatibility of the multi-nozzle head 13 can be simplified. Also, the first type shown in FIG.
In the embodiment, the adhesive 18b for fixing the piezoelectric member 17 and the non-piezoelectric member 18 to each other is
May be provided only at both ends in the width direction. In this case, too, the distance between the piezoelectric member 17 and the non-piezoelectric member 18 is sufficiently small, so that the pressure in the ink chamber 29 does not decrease. When the convex portion 17a vibrates, the distortion of the portion other than the convex portion 17a is absorbed and slipped at this interval, and the ink can fly at high speed without crosstalk.

In the above embodiment, the ink supply slit 35 is provided in the non-piezoelectric member 18 so as to supply ink to the ink chamber 29 through the hole 24 of the ink lid 20. Various supply configurations are known, and for example, a configuration in which ink is supplied from the side of the closing plate 21 by an ink supply tube can be arbitrarily selected.

[0043]

As described above, according to the ink jet head of the present invention, the plurality of convex portions of the piezoelectric member and the corresponding plurality of concave portions of the non-piezoelectric member are fitted to each other. An ink chamber is formed between the tip surface and the bottom surface of each recess. Therefore, an inkjet head can be formed with a simple configuration. Moreover, since the upper and side surfaces of each of the protrusions are coated with an insulating material, the current flowing through each of the protrusions does not leak through the ink, and ink with low resistance can be used. Then, the bottom surface of each concave portion formed between each convex portion of the piezoelectric member and the distal end surface of each convex portion formed between each concave portion of the non-piezoelectric member, which faces the bottom surface, and Since the member and the non-piezoelectric member are constrained so that the respective contact surfaces do not move away from each other, a convex portion of the piezoelectric member is driven, and ink formed by the convex portion and the concave portion of the non-piezoelectric member is formed. When pressure is applied to the chamber, even if the internal pressure of the ink chamber rises instantaneously, the displacement of the non-piezoelectric member due to the pressure can be suppressed, and a normal amount of ink can be reduced by the applied pressure. And good image quality can be obtained.
Further, since a gap is formed between the side surface of each convex portion of the piezoelectric member and the side surface of each concave portion of the non-piezoelectric member facing the side surface of each convex portion, the deformation of each convex portion of the piezoelectric member Can be performed promptly and satisfactorily without being restricted by the non-piezoelectric member, and there is an effect that the discharge efficiency is improved.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the multi-nozzle head.

FIG. 3 is a perspective view showing the first embodiment.

FIG. 4 is a sectional view in a width direction of a main part of the first embodiment.

FIG. 5 is a sectional view in a depth direction of a main part of the first embodiment.

FIG. 6 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 7 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 8 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 9 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 10 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 11 is a perspective view illustrating a manufacturing process of the first embodiment.

FIG. 12 is a perspective view illustrating a manufacturing process of 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 widthwise partial front view showing a modification of the first embodiment.

15 is a partial sectional view in the depth direction of FIG. 14;

FIG. 16 is a partial sectional view in the width direction showing a modification of the first embodiment.

FIG. 17 is a partial sectional view in the width direction of the second embodiment.

FIG. 18 is a perspective view illustrating a manufacturing process of the second embodiment.

FIG. 19 is a perspective view illustrating a manufacturing process of the second embodiment.

FIG. 20 is a perspective view illustrating a manufacturing process of the second embodiment.

FIG. 21 is a partial sectional view in the width direction showing a modification of the second embodiment.

FIG. 22 is a partial sectional view in the width direction showing a third embodiment.

FIG. 23 is a partial sectional view in the width direction showing the fourth embodiment.

FIG. 24 is a partial sectional view in the width direction showing the fifth embodiment.

FIG. 25 is a partial sectional view in the width direction showing a sixth embodiment.

FIG. 26 is a partial sectional view in the width direction showing a seventh embodiment.

FIG. 27 is a perspective view showing a modification of the first embodiment.

FIG. 28 is a perspective view showing a modification of the first embodiment.

FIG. 29 is a diagram showing the shape of a nozzle hole.

FIG. 30 is a schematic view showing a fixing means of the embodiment.

FIG. 31 is a partial sectional view in the width direction showing a conventional example.

[Explanation of symbols]

 17: Piezoelectric member 17a: Convex part 18: Non-piezoelectric member 18a: Concave part 19a: Nozzle hole 29: Ink chamber 32: Individual electrode 33: Common electrode

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/045

Claims (2)

(57) [Claims] 1. A piezoelectric member having a plurality of projections having an upper surface and side surfaces coated with an insulating coating, at least a part of the projections being a piezoelectric body, and each of the plurality of projections in the piezoelectric member A non-piezoelectric member made of a non-piezoelectric body having a plurality of concave portions fitted into the ink container, wherein an ink chamber is formed between a tip end surface of each of the convex portions and a bottom surface of each of the concave portions facing each other. An inkjet head, wherein the bottom surface of each concave portion formed between each convex portion of the piezoelectric member,
The bottom surface and the tip surface of each convex portion formed between each concave portion of the non-piezoelectric member are in contact with each other, and the piezoelectric member and the non-piezoelectric member do not move in the direction in which each contact surface separates. The piezoelectric member is constrained and faces the side surface of each convex portion of the piezoelectric member and the side surface of each convex portion.
A gap is formed between the side surface of each concave portion of the non-piezoelectric member.
Ink jet head, characterized by being. (2) The insulating coating may be an amorphous
Characterized by being formed by a film containing carbon carbon
The inkjet head according to claim 1.