JP3250402B2 - Ink jet recording device - Google Patents

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 an on-demand type ink jet head for performing recording on a recording medium such as paper by causing ink droplets to fly according to an image signal.

[0002]

2. Description of the Related Art Conventionally, a voltage is applied to a piezoelectric body in accordance with an image signal, and ink is pressurized based on the deformation of the piezoelectric body to cause ink droplets to fly from a nozzle, thereby recording on a recording medium such as paper. On-demand type inkjet heads are used in recording devices such as printers.

As an ink jet head of this type,
For example, Japanese Patent Application Laid-Open No. Sho 62-56150 discloses the configuration shown in FIG. This inkjet head 60
Has a piezoelectric member 62 in which a plurality of recesses 61 are formed, and a cover plate 63 that covers the plurality of recesses 61, and an ink chamber 64 is formed inside the recess 61. Also,
A convex portion 65 is formed on the bottom surface of the plurality of concave portions 61,
Electrodes 66 and 67 are provided on the upper surface of the convex portion 65 and on the rear surface of the piezoelectric member 62 at positions corresponding to the convex portion 65, respectively. In the ink jet head 60 configured as described above, a voltage is applied between the electrodes 66 and 67,
By deforming the convex portion 65 of the piezoelectric member 62, the volume of the ink chamber 64 is changed, and the ink filled in the ink chamber 64 is pressurized so that ink droplets are ejected from the nozzles.

Japanese Patent Laid-Open Publication No. Hei 6-143563 proposes the one shown in FIG. The inkjet head 70 has a plurality of recesses 71 for the ink chamber 74.
An elastic film 73 is joined on a flow path substrate 72 made of a non-piezoelectric body and formed in parallel. On the elastic film 73, a plurality of laminated piezoelectric vibrators 76 for driving and a laminated piezoelectric vibrator 77 for dummy bonded to the substrate 75 are arranged. Driving laminated piezoelectric vibrator 76 and dummy laminated piezoelectric vibrator 77
Is obtained by bonding a plate composed of one laminated piezoelectric vibrator to a substrate 75 and then separating the plate by slit processing.
The joined body of the flow path substrate 72, the elastic film 73, the laminated piezoelectric vibrators 76 and 77, and the substrate 75 is held between two rigid fixing plates 78 and 79. In the ink jet head 70 configured as described above, a voltage is applied to the driving laminated piezoelectric vibrator 76 to deform it, and the volume of the ink chamber 74 is changed via the elastic film 73 to pressurize the ink. Ink droplets fly from the nozzles.

Further, Japanese Patent Laid-Open Publication No. Hei 6-71878 proposes an ink jet head shown in FIG. The ink jet head 80 presses the ink chamber 84 via the elastic film 83 by the pressure generating member 86 like the ink jet head 70 to fly ink droplets. In a stationary state, it is slightly pushed into the inside of the ink chamber 84. In this case, the distal end portion of the pressure generating member 86 and the elastic film 83 are not bonded, and a quarter of the natural vibration period of the elastic film 83 forming one wall of the ink chamber 84 is equal to that of the pressure generating member 86. It is longer than the contraction time. For this reason, when the pressure generating member 86 is deformed from the stationary state and further lifts up the elastic film 83 to cause the ink droplets to fly and then recovers, the elastic film 83 does not follow the pressure generating member 86 and 86 and temporarily retreats.

[0006]

However, each of the above-mentioned ink jet heads has the following problems. First, in the ink jet head 60, the protrusion 6
Even if the ink is pressurized by deforming the ink 5, the protrusion 65
Not only does the flying efficiency decrease by going around the gap formed between the protrusions 65 and the sidewalls of the recesses 61, but also the protrusions 6, which are piezoelectric bodies, are in direct contact with the ink.
5 penetrates the ink and causes a reduction in resistance, so that an effective voltage is not applied. As a result, there is a problem that the amount of displacement of the convex portion 65 decreases and ink droplets do not easily fly.

Further, in the ink jet head 70, the contact surface between the laminated piezoelectric vibrator 76 for driving and the substrate 75 extending in the depth direction (the direction of the front and back of the paper in FIG. 24) is bonded and fixed over the entire surface. In addition, each vibration of the laminated piezoelectric vibrator 76 propagates to the adjacent laminated piezoelectric vibrator 76 via the substrate 75 to cause an interlocking displacement.
For this reason, ink droplets are ejected from the ink chamber 74 that does not want to eject ink, or the flow of ink in the ink chamber 74 is disturbed even before the ink droplets are not ejected, and the ink droplets are ejected at the next ejection. There is a problem that mutual interference of ink discharge characteristics, called so-called crosstalk, occurs in which the diameter becomes non-uniform, resulting in poor print quality. In addition, in the inkjet head 70, the laminated piezoelectric vibrator 77 for the dummy is formed by the elastic film 73 and the substrate 7.
Since the elastic film 73 covering the ink chamber 74 has a planar shape and plays a role of a spacer between the elastic film 73 and the laminated piezoelectric vibrator 76, the elastic film 73 itself also vibrates with the vibration of the laminated piezoelectric vibrator 76. Therefore, in order to stably perform the next ejection of ink droplets, it is necessary to wait until the vibration of the elastic film 73 stops, and there is a problem that the high-frequency response required when increasing the printing speed is lacking.

Further, in the ink jet head 80, the ink chamber 84 of the elastic film 83 by the pressure generating member 86 is also provided.
After the elastic film 83 is once separated without following the restoring operation of the pressure generating member 86,
Since it is restored gradually and comes into contact with the pressure generating member 86 again, there is a problem that the high frequency response is lacking similarly to the ink jet head 70 described above. Further, in the pressure generating member 86 of the ink jet head 80, a voltage is applied to a thin rectangular plate on which the piezoelectric material is laminated to vibrate in a length direction orthogonal to the polarization direction of the piezoelectric material. Is used, bending deformation is likely to occur during repeated use, and the deformation stability is lacking. As a result, there is a problem that ink flying varies, and the diameter of dots adhering to recording paper is not stable.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide an ink jet recording apparatus which realizes highly efficient and stable flying of ink droplets and has excellent high frequency response.

[0010]

In order to achieve the above object, an ink jet recording apparatus according to the present invention has a plurality of groove-shaped first recesses serving as ink chambers formed in a non-piezoelectric member. A substrate is provided on the first concave portion forming surface, and an ink jet head in which a plurality of piezoelectric bodies are arranged at positions corresponding to the concave portions on the substrate, and ink filled in the ink chamber by operating the piezoelectric bodies. A voltage applying means for applying a voltage to the piezoelectric body in accordance with an image signal so as to perform pressurized ejection, wherein the substrate corresponds to the plurality of first concave portions of the non-piezoelectric member. Forming a plurality of groove-shaped second recesses having a depth shallower than the height of the piezoelectric body, disposing the piezoelectric body in each of the second recesses, covering the first recess, and forming a wall of the first recess. Ink chamber between Forming partition walls provided, the first of the partitions a portion of the piezoelectric body is fitted in the first recess
The piezoelectric body is pressed so as to bend into the inside of the concave portion, and at least a part of the piezoelectric body is not fixed to the substrate, and an unfixed part of the piezoelectric body acts.

Further, in the ink jet recording apparatus of the present invention, a plurality of groove-shaped concave portions serving as ink chambers are formed in the non-piezoelectric member, a substrate is provided on the concave portion forming surface of the non-piezoelectric member, and An inkjet head in which a plurality of piezoelectric bodies are arranged at corresponding positions, and a voltage applied to the piezoelectric bodies in response to an image signal so that the piezoelectric bodies act to pressurize and discharge the ink filled in the ink chamber. An ink-jet recording apparatus comprising: a voltage applying means for applying an ink; a portion that forms an ink chamber between itself and the wall surface of the concave portion by covering the concave portion or partitioning the inside of the concave portion; A bulge is provided to abut against the piezoelectric body, and at least a portion of the piezoelectric body is not fixed on the substrate, and an unfixed portion of the piezoelectric body acts. Those who like to make.

In the ink jet recording apparatus of the present invention, one end of the piezoelectric body may be fixed to the substrate, and the other end may not be fixed.

Further, in the ink jet recording apparatus of the present invention, when a voltage is applied to the piezoelectric body, an unfixed portion of the piezoelectric body acts to separate the partition forming the ink chamber from the substrate. It may be displaced in a direction or a direction toward the substrate.

Further, in the ink jet recording apparatus of the present invention, the piezoelectric body is not fixed to the substrate at least in a region corresponding to the ink chamber, and is held between the partition and the substrate. An electric field is formed inside the piezoelectric body in parallel to the polarization direction, and the unfixed portion of the piezoelectric body is caused to act on the ink chamber using a thickness direction vibration mode in which the piezoelectric body vibrates in the thickness direction. Is also good.

In the ink jet recording apparatus according to the present invention, the piezoelectric body may be a columnar body elongated in a direction along the ink chamber, or may be formed in a comb-like shape having a portion where each of the piezoelectric bodies is connected. It may be formed. Also,
In the inkjet recording apparatus of the present invention, the non-piezoelectric member has a first convex portion defined between the first concave portions, while the substrate has a second convex portion defined between the second concave portions. And the first convex portion and the second convex portion may sandwich the partition.

[0016]

In the ink jet recording apparatus having the above-described structure, when a voltage is applied to the piezoelectric body to form an electric field, a portion of the piezoelectric body that is not fixed is deformed. Based on this deformation, the partition is pushed up sharply, and the volume of the ink chamber decreases,
The ink filled in the ink chamber is discharged under pressure.
On the other hand, when the voltage application to the piezoelectric body is canceled and the electric field is extinguished, the unfixed portion of the piezoelectric body returns to the original state. At this time, the partition wall follows and returns to the original state while always in contact with the returning piezoelectric element. As a result, the volume of the ink chamber is increased and a negative pressure is generated inside the ink chamber, and the ink is replenished to prepare for the next ink ejection.

In this case, the piezoelectric body is fixed to the substrate at a part of its contact surface or is not fixed at all. No talk occurs. In addition, since a partition is provided between the ink chamber and the piezoelectric body, the ink does not directly contact the piezoelectric body and penetrate.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. [First Embodiment] FIG. 1 schematically shows the entire configuration of an ink jet recording apparatus according to a first embodiment of the present invention. The ink jet recording apparatus 1 is roughly divided into a power supply section 2 having a connector 2a, a drive system 3, a mechanical controller 4, a memory 5, a controller 6, an ink supply section 7, a scan carriage 8, It comprises a unit 9, a case 10, and an operation panel 11. The scan carriage 8 is capable of scanning in a direction perpendicular to the paper passing direction (the direction of arrow a) (the front and back sides of the paper surface in FIG. 1), and has four insides for black, cyan, magenta, and yellow. The two inkjet heads 12 are arranged along the paper passing direction, and the ink discharge nozzles are directed downward.

Next, the structure of the ink jet head 12 will be described with reference to FIGS. As shown in FIG. 2, the ink-jet head 12 has a configuration in which an ink discharge unit 14, a terminal plate 15, and a connector 16 are sequentially installed on a base plate 13 from the front (lower left in FIG. 2).

The top plate 20 of the ink discharge section 14 is formed of a plate made of a non-piezoelectric material such as alumina, for example.
As shown in FIG. 3, a plurality of groove-shaped concave portions 21 are formed on the lower surface thereof. These recesses 21 are formed at a predetermined pitch in the width direction of the top plate 20, and extend in parallel with the longitudinal direction of the top plate 20. A partition wall 22 made of, for example, an aramid resin is adhered to the surface of the top plate 20 where the concave portion 21 is formed.
An ink chamber 23 is formed inside the concave portion 21 covered by the partition wall 22.

On the side of the top plate 20 where the recess 21 is formed, the partition 2
2, a substrate 24 is provided. The substrate 24 is made of a non-piezoelectric material similarly to the top plate 20, and a concave portion 25 is formed on a surface facing the concave portion 21.

On the bottom surface 25 a of the concave portion 25 formed in the substrate 24, a plurality of piezoelectric bodies 26
It is arranged corresponding to. The piezoelectric body 26 is made of, for example, PZT.
It is made of piezoelectric ceramic and forms an elongated columnar body in the direction along the ink chamber 23, and its upper part is fitted shallowly along the recess 21 of the top plate 20. Thereby, the partition wall 22 is in a state of being bent and pushed into the inside of the ink chamber 23.
An individual electrode 27 is provided on the upper surface of the piezoelectric body 26 in contact with the partition 22.
On the other hand, a common electrode 28 is provided on the lower surface of the piezoelectric body 26 in contact with the substrate 24. Note that, as shown in FIG. 3, the polarization direction (the direction of the arrow b) of the piezoelectric body 26 is arranged so as to be parallel to the direction of an electric field formed by applying a voltage to the individual electrode 27 and the common electrode 28. Have been. The surface of the piezoelectric body 26 on which the individual electrodes 27 are formed and the partition wall 22 may or may not be bonded. However, if bonded, the partition wall 22 can more reliably follow the displacement of the piezoelectric body 26 and the high-frequency response is improved. .

As shown in FIG. 4, the piezoelectric body 26 is provided on the substrate 2 in a region s on the rear end side (right side in FIG. 4).
4 is adhered and fixed with a conductive adhesive, and its front end is a free end. As a result, when a voltage is applied to the piezoelectric body 26 to form an electric field, an unfixed portion of the piezoelectric body 26 located in front of the bonding area s with the substrate 24 acts to push up the partition wall 22 and raise the ink chamber 23. Will be pressurized.

A nozzle plate 30 made of, for example, a polyimide film having a thickness of about 25 to 200 μm is adhered and fixed to the front end surface of the joined body of the top plate 20, the partition wall 22, and the substrate 24. In the nozzle plate 30, a plurality of nozzle holes 30a are formed at the same pitch as the ink chamber 23 by, for example, an excimer laser, and the pitch is, for example, about 42.3 to 254 μm (pixel density: 600 to 1).
00 dpi).

As shown in FIG. 2, side plates 31, 31 for closing the openings at both ends of an ink inlet (not shown, described later) communicating with each ink chamber 23 are formed on both side surfaces of the top plate 20, as shown in FIG. A back plate 32 is attached to the rear end surface of the top plate 20 to close the rear end opening of each ink chamber 23.
Is glued. A manifold 33 for supplying ink to the ink chamber 23 is adhered to the upper surface of the top plate 20, and a plurality (only one) of ink supply ports 33a protrude from the upper part of the manifold 33. ing. In this embodiment, the ink is supplied from the upper surface of the top plate 20 to each of the ink chambers 23, but may be supplied from the rear end side of each of the ink chambers 23.

As shown in FIG. 2, the piezoelectric body 26 extends backward beyond the back plate 32 adhered to the rear end of the top plate 20. The individual electrodes 27 at the rear end of each piezoelectric body 26 are connected to a plurality of conductors 15a provided on the upper surface of the terminal plate 15 by wire bonding, respectively, and furthermore, a voltage is applied through a driving IC 17, a conductor 15b and a connector 16. The controller 6 (FIG. 1)
The controller 6 applies a voltage to the piezoelectric body 26 according to an image signal. On the other hand, substrate 2
4 is electrically connected to the common electrode 28 of each piezoelectric body 26 via a conductive adhesive layer, and thus the rear end surface 24a of the substrate 24 and the conductor 13a provided on the base plate 13 Are connected by one wire bonding or the like, each common electrode 28 is connected to the controller 6 via the connector 16.

Next, a process of manufacturing the ink jet head 12 having the above-described configuration will be described with reference to FIGS. First, as shown in FIG.
An Au / Ni film or an Au / (Ni, Cr) sputtered film of 10 μm to 0.1 μm is formed on the upper and lower surfaces of the PZT plate 40 by electroless plating, and an electrode layer is provided. To the concave bottom surface 2 of the substrate 24.
5a is bonded using a conductive adhesive. In this case, the bonding area s is only the rear end side (the right side in FIG. 5A) of the PZT plate 40, and the front end side is in a non-adhered state.

Then, as shown in FIG. 5B, the PZT plate 4 is
0 is slit, and the piezoelectric bodies 26 are formed at a predetermined pitch as shown in FIG. Thereafter, in order to prevent the displacement when a voltage is applied to the piezoelectric body 26 from being reduced due to the penetration of moisture in the atmosphere, for example, a polyimide resin is applied to the entire surface of the piezoelectric body 26 by a spin coating method, Bake at 180 ° C for 1 hour to perform overcoat treatment. However, when a piezoelectric material having high humidity resistance is used for the piezoelectric body 26, this step may be omitted.

On the other hand, as shown in FIG. 6, a ceramic plate 41 made of, for example, alumina is used for the top plate 20.
The plurality of recesses 21 to be the ink chambers 23 are formed at an equal pitch with the piezoelectric body 26 by dicing. The width of these recesses 21 is set so that the piezoelectric body 26 can be loosely fitted.
Form larger dimensions. Further, a groove-shaped ink inlet 42 which is orthogonal to the recess 21 and communicates with all the recesses 21 is formed on the surface opposite to the surface on which the recesses 21 are formed by dicing. Thereafter, the partition wall 22 is bonded to the surface of the top plate 20 where the concave portions 21 are formed.

Subsequently, as shown in FIG. 7, the top plate 20 is superimposed on the substrate 24, and both ends in the width direction are bonded and fixed, and the front end surface of the joined body of the top plate 20 and the substrate 24 is attached to the top plate. The nozzle plate 30 is bonded so that the nozzle hole 30a is located at the center of the ink chamber 23.

As shown in FIG. 8, a manifold 33 is adhered and fixed on the ink inlet 42, and side plates 31, 31 for closing both side openings of the ink inlet 42, and a rear end opening of the ink chamber 23 are provided. By bonding the back plate 32 and the back plate 32 to the top plate 20, the assembly of the ink discharge unit 14 is completed.

Further, as shown in FIG. 9, the ink ejection section 14 and a driving IC 17 and conductors 15a,
The terminal plate 15 on which the conductor 15a is installed and the connector 16 are bonded and fixed to the upper surface of the base plate 13 on which the conductor 13a is installed. Then, the individual electrode 27 of the piezoelectric body 26 and the conductor 15
a, the rear end surface 24a of the substrate 24 that is conductive to the common electrode 28 of each piezoelectric body 26 and the conductor 13a on the base plate 13
Are electrically connected to each other, and the conductors 15b and 13a are electrically connected to the terminals 16a of the connector 16, whereby the ink jet head 12 is completed. Thereafter, as shown by a dotted line in FIG. 9, if the outer surface is integrally molded with resin, more reasonable fixing can be achieved.

Next, the ink jet head 1 of this embodiment
2 will be described. As shown in FIG. 4, the ink is supplied from the ink supply unit 7 (see FIG. 1) via the ink supply port 33 a of the manifold 33, and is filled in the ink chamber 23 in the top plate 20. When a pulse-like voltage as shown in FIG. 10A is applied to the individual electrode 27 and the common electrode 28 in accordance with the image signal, the polarization direction (the direction of the arrow b in FIGS. 12 and 13) is generated in the piezoelectric body 26. An electric field is formed in parallel. At this time, if the piezoelectric body 26 is not bonded and fixed to the substrate 24 at all,
As shown by the dotted line in FIG. 11, while being expanded and deformed by Δy in the y direction, it is slightly contracted and deformed in the x direction and the depth direction (the front and back sides of the paper surface in FIG. 11). When the entire surface of the piezoelectric body 26 is adhered to the substrate 24, the substrate 24 is distorted in accordance with the deformation of the piezoelectric body 26, and as shown by a dashed line in FIG.
The surface has a phenomenon that the expanded portion and the contracted portion are mixed and deformed in a wavy manner, and the amount of deformation required for ink flying as a whole of the piezoelectric body 26 is greatly lost.

On the other hand, as in the structure of this embodiment, the bonding area s
_{In the case where 2} is a part of the contact surface with the substrate 24 and one end of the piezoelectric body 26 is a free end, as shown by a dotted line in FIG. 12, the free end warps with a curvature in a direction away from the substrate. It has been confirmed that the displacement ΔY in the y direction at this time is larger than the above Δy when the same voltage is applied.

The unfixed portion of the piezoelectric body 26 acts due to this warping deformation, and as shown in FIG.
2 is steeply pushed into the concave portion 21 to reduce the volume of the ink chamber 23, whereby the pressurized ink is ejected and flies in the form of droplets from the nozzle holes 30a, and adheres to recording paper (not shown). . When the voltage between the individual electrode 27 and the common electrode 28 becomes zero, the piezoelectric body 26 returns to the original state. At this time, the partition wall 22 has elasticity and the concave portion 2 in the initial state.
1 is pushed into the ink chamber 23 by the piezoelectric body 26 fitted shallowly to the piezoelectric body 26, so that the piezoelectric body 26 always follows the piezoelectric body 26 performing the restoring operation. As a result, the volume of the ink chamber 23 increases, ink is supplied to the ink chamber 23 via the manifold 33 and the ink inlet 42, and the preparation for the next ink ejection can be made.

However, at the time of the above ink supply, FIG.
As shown in FIG.
When the ink chamber 23 is restored based on the elasticity of the ink and the volume of the ink chamber 23 is sharply increased, air bubbles are sucked into the ink chamber 23 from the nozzle holes 30a, and when the next pulse voltage is applied, the air bubbles absorb the pressure to cause the ink to fly. May hinder. For this reason,
As shown in FIG. 10B, the piezoelectric body 26 has a slope in the pulse shape of the voltage at the time of the restoring operation, and the piezoelectric body 26 and the partition wall 22 return fastest in a range where no air bubbles are sucked. Prevent this.

By applying a pulse voltage with the same voltage but a different pulse width to that of FIG. 10 (a), the diameter of the flying ink droplet can be changed, thereby changing the diameter of the dot adhering to the recording paper. Therefore, halftone reproduction becomes possible. For example, as shown in FIG. 10C, when the pulse width is reduced, the dot diameter is reduced. The pulse voltage shown in FIG. 10D is obtained by applying a small pulse after the small voltage with the opposite polarity to the main pulse. If a pulse voltage having this waveform is applied to the piezoelectric body 26, the ink column extending from the nozzle hole 30a after the ink droplet flies by the main pulse is drawn into the ink chamber 23 by the sub-pulse, so that satellite noise can be reduced. The pulse voltage shown in FIG. 10 (e) applies a small voltage preceding pulse having the same polarity as the main pulse. According to the pulse voltage having this waveform, the voltage value of the main pulse can be suppressed low. As a result, the burden on the driver is reduced, and the driver cost can be reduced.

The above-described ink ejection operation is performed independently for each of the ink chambers 23 in accordance with the image signal, whereby an image for one line is drawn, and this is repeated in synchronization with the movement of the recording paper. Thus, an image corresponding to the image signal is drawn on the recording paper.

As described above, in the ink jet head 12 of this embodiment, the bonding area s ₁ between the piezoelectric body 26 and the substrate 24 is provided.
As a part of the entire length of the piezoelectric body 26, the interlocking displacement caused by the vibration of the piezoelectric body 26 when a voltage is applied being propagated to the adjacent piezoelectric body 26 via the substrate 24 is completely suppressed. can do. Therefore, it is possible to perform the ink ejection very stably without unnecessary ink ejection due to crosstalk and disturbance of the ink flow in the ink chamber 32, and as a result, it is possible to significantly improve the print quality. become.

Further, since the piezoelectric body 26 is partially adhered, a remarkably large displacement can be obtained at the same voltage as compared with the conventional example, and the displacement is almost proportional to the applied voltage. In a relationship. Therefore, in order to secure the same ink ejection amount and flying speed as in the conventional case, an extremely low voltage is sufficient, and the driver cost can be reduced, and the applied voltage is controlled by the voltage value, the pulse width, or a combination thereof. The diameter of the flying ink droplet can be arbitrarily changed by adjusting the displacement amount of the piezoelectric body 26. As a result, it is possible to reproduce the halftone of the color of the image drawn on the recording paper.

Further, the piezoelectric body 26 is provided in the concave portion 21 of the top plate 20.
The partition wall 22 is bent and pushed into the ink chamber 23 by fitting into the ink chamber 23. Therefore, the piezoelectric body 2
Since the displacement of 6 is used to surely reduce the volume of the ink chamber 23 without any loss, highly efficient ink flying is achieved. Further, since the partition wall 22 follows the deformation of the piezoelectric body 26 while always keeping the state of contact with the piezoelectric body 26, high-frequency response can be improved, and as a result, the printing speed can be increased.

Further, since the piezoelectric body 26 is separated from the ink chamber 23 by the partition wall 22 and is not in direct contact with the ink, the ink does not penetrate into the piezoelectric body 26 and the resistance is not reduced. Therefore, it is possible to prevent the displacement of the piezoelectric body 26 from decreasing with a decrease in the effective voltage, and as a result, the stability and reliability of the inkjet head 12 are improved.

Next, a modification of the first embodiment will be described with reference to FIGS. In the inkjet head 12 of the first embodiment, the substrate 24 on which the concave portion 25 is formed is used. However, as shown in FIG. 14, a substrate 43 having a flat upper surface is used, and spacers 44, 44 (one is (Not shown) may be arranged. By doing so, it is not necessary to give the substrate 43 a special shape, which facilitates molding and leads to cost reduction. Further, as shown in FIG. 15, at the position facing the concave portion 21 of the top plate 20, substrates 46 each having a concave portion 45 having the same width as the concave portion 21 and a depth smaller than the height of the piezoelectric body 26 are used. By doing so, the partition wall 22 is clamped from above and below,
Since each ink chamber 23 is partitioned,
Propagation of the vibration of the partition wall 22 to the adjacent ink chamber 23 can be more suitably blocked.

In the first embodiment and its modifications, the pulse voltage shown in FIGS. 10 (a) to 10 (e) is applied to make the unfixed portion of the piezoelectric body 26 act, and
2 is displaced away from the substrate 24 to fly the ink, and the ink is replenished when the piezoelectric body 26 is restored. On the contrary, as shown in FIG. 10 (f) or (g). After applying a pulse and displacing the partition 22 in the direction toward the substrate 24 by the action of the unfixed portion of the piezoelectric body 26 to replenish the ink, the ink is caused to fly when the piezoelectric body 26 is restored. Is also good. Here, the reason why the rising portion of the pulse in FIG. 10 (g) is inclined is the same as in the case of FIG. 10 (b).

[Second Embodiment] Next, an ink jet recording apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

As shown in FIG. 16, the ink ejection portion of the ink jet head of the present embodiment includes a top plate 20 in which a plurality of groove-shaped recesses 21 are formed at a predetermined pitch, and a recess corresponding to these recesses 21. A recess 47a having the same width as 21
Are formed on the substrate 47, the piezoelectric bodies 26 respectively disposed on the bottom surfaces of these concave portions 47a in a partially adhered state similarly to the first embodiment, and are disposed between the top plate 20 and the substrate 47. , And a partition wall 48 that forms the ink chamber 23 with the wall surface of the concave portion 21. As shown in FIG. 17, a plurality of grooves 49 bulging in an arc shape along each recess 21 and having a cross section toward the bottom surface of the recess 47a.
Are formed by film insert molding, and when assembled, the bottoms 49a of these grooves 49 are
6 to come into contact with the upper part. The configuration other than the above is the same as that of the first embodiment, and thus the description is omitted.

In the ink jet head according to the second embodiment having the above-described configuration, the same effect as that of the first embodiment can be obtained, and since the groove 49 has a swelling shape, restoration after being pushed in becomes faster. . Therefore, the ability to follow the piezoelectric body 26 vibrating at a high cycle is improved, and the printing speed can be increased. Also, the bottom 49a of the groove 49
If the piezoelectric body 26 and the piezoelectric body 26 are bonded, the high-frequency response is further improved, and the printing speed can be increased.

Further, as a modification of the second embodiment, FIG.
As shown in FIG. 8, the concave portion 21 of the top plate 20 is formed deeper than that of the second embodiment, and the partition walls 35 formed integrally with the top plate 20 are formed inside the concave portion 21 to form a flat plate. The concave portion 21 is formed in the piezoelectric body 26 disposed on the substrate 50 of FIG.
The top plate 20 and the substrate 50 may be overlapped and fixed in a state in which are completely fitted, and the bottom 35 a of the partition wall 35 may be in contact with the upper portion of the piezoelectric body 26. According to this modification, not only the same effects as in the second embodiment can be obtained, but also the number of parts in the process is substantially reduced, so that the cost can be reduced by reducing the number of processes. In this case, the partition wall 35 is integrally formed of the same material as the top plate 20 by resin molding.

In the above-described embodiment and its modifications, the single-layer piezoelectric body 26 is used. However, as shown in FIG. 19, two or more piezoelectric materials are laminated by a known green sheet method. If the stacked piezoelectric body 55 in which the individual electrodes and the common electrode are arranged is used, a large effective displacement can be obtained in accordance with the number of stacked layers, so that the driving voltage can be further reduced and the driver cost is reduced. Reduction can be achieved.

Next, a third embodiment using the laminated piezoelectric element 55 will be described with reference to FIGS. Third
In the ink jet head of the embodiment, as shown in FIG. 20, the substrate 46 used in the modification of the first embodiment and having the recess 45 formed opposite to the recess 21 of the top plate 20 is used.
(See FIG. 15), the laminated piezoelectric body 55 is
19, at least in the area corresponding to the ink chamber 23, specifically, in the S3 area shown in FIG. It is sandwiched and held between.
On the other hand, the laminated piezoelectric body 55 is adhered to the substrate 46 in a rear end region not corresponding to the ink chamber 23, specifically, in a region S4 shown in FIG. This is because the multilayer piezoelectric body 55 needs to be accurately positioned with respect to the substrate 46 when performing wire bonding to the individual electrodes of each multilayer piezoelectric body 55.

When a voltage is applied to the laminated piezoelectric body 55, almost all of the S3 region except for the vicinity of the S4 region adhered to the substrate 46 expands by ΔY in the y direction as shown by a dotted line in FIG. And shrinks in the x direction and the depth direction (in FIG. 21, the front and back sides of the paper).
It shows the same deformation as when it is not bonded to the substrate 46 at all. On the other hand, since the internal electrode of either the individual electrode or the common electrode is not provided in the S4 region of the multilayer piezoelectric body 55, no electric field is formed inside and no deformation occurs.

The deformation in the S3 region uses a thickness vibration mode in which each layer of the piezoelectric material is deformed in the thickness direction (y direction) by an electric field being formed in parallel with the polarization direction. Are added by the number of layers, and the deformation amount Δy when the same voltage is applied to the single-layer piezoelectric body 26
A larger deformation amount ΔY can be obtained as compared with (see FIG. 11). Due to this deformation, the S3 region of the multi-layer piezoelectric body 55 acts, and as shown by the dotted line in FIG. 20, the partition 22 is pushed up sharply to reduce the volume of the ink chamber 23. The droplets fly from the holes 30a.

As described above, in the ink jet head according to the third embodiment, the S3 region serving as the operating portion of the multilayer piezoelectric body 55 is not fixed to the substrate 46, and the upper surface of the S3 region that is in contact with the partition wall 22 is formed. In the thickness direction vibration mode, the ink chamber 23 is uniformly expanded and displaced by ΔY and pressurizes the ink chamber 23, so that the upper surface of the piezoelectric body is distorted as if wavy as in the case where the entire surface is bonded to the substrate, and the displacement is lost. In addition, unlike the case where the longitudinal elongation vibration mode is used, the piezoelectric body does not bend and deform, the pressurized state of the ink chamber 23 changes, and the flying ink droplet diameter does not become unstable. Therefore, according to the present embodiment, efficient and stable ink flying can be achieved.

In the third embodiment, the step S4 is performed in order to accurately position the laminated piezoelectric body 55 with respect to the substrate 46.
The width of the concave portion 45 corresponding to the S4 region is partially formed to be substantially equal to the width of the laminated piezoelectric body 55, and the S4 region is press-fitted to the concave portion 45.
The stacked piezoelectric body 55 may be fixed by being sandwiched between the wall surfaces. In this case, the laminated piezoelectric body 55 is
The purpose of positioning with respect to the substrate 46 is achieved without any adhesion to the substrate 6, and the same effect as in the third embodiment can be obtained. Further, if the multilayer piezoelectric body 55 can be positioned with respect to the substrate 46 by a method other than bonding or clamping, the entire multilayer piezoelectric body 55 may be held by merely sandwiching it between the partition wall 22 and the substrate 46.

By the way, FIGS.
In the embodiment shown in FIGS.
And concave portions 45, 4 of the substrates 46, 47 or the top plate 20.
The distance between the side walls 7 and 21 is preferably 50 μm or less, and more preferably 20 μm or less. As a result, the pressure loss when the partition 22 is pushed up to pressurize the ink chamber 23 is reduced, which enables low-voltage driving and increases the driving stability of the piezoelectric bodies 26 and 55.

In the above-described embodiments and their modifications, as shown in FIG. 5, a flat plate-like piezoelectric material partially fixed to the substrate 24 in a bonded state is diced to form each piezoelectric body 26. Although it was completely divided and formed into a strip shape, FIG.
2, a so-called comb-shaped piezoelectric member 5
1 may be used. In the piezoelectric member 51, in the front region (left side in FIG. 22) including the bonding region s with the substrate, each piezoelectric body 52 is divided into strips.
In the rear area of the bonding area s, the piezoelectric bodies 52 are connected via a connecting portion 53 having an upper surface one step lower than the upper surface of each piezoelectric body 52 on which the individual electrode is formed.
The connecting portion 53 is formed by making the cutting depth shallow after passing the bonding region s with the substrate when slitting a flat plate-shaped piezoelectric material by dicing.

With this configuration, each piezoelectric body 52
Increases the structural strength of the inkjet head,
Reliability is improved. Further, since the common electrode formed on the lower surface of each piezoelectric body 52 is connected in the rear region of the piezoelectric member 51 due to the presence of the connection portion 53, the connection between the common electrode and the driver power supply is established at this rear portion. The connection is completed by connecting the common electrode in the region and the conductor 13a on the base plate 13 at one place by wire bonding or soldering. Therefore, the piezoelectric body 2 is separated into strips.
It is not necessary to use a conductive adhesive for bonding to the substrate 24 as in the case of forming 6.

Further, by forming the piezoelectric member 51 in a comb-teeth shape, handling of the processing / assembly surface becomes easy,
Since the variation in assembly is reduced, the manufacturing cost can be reduced.

Next, materials and the like that can be used in the above-described embodiments and modifications will be described. Material of Piezoelectric Material As the material of the piezoelectric materials 26, 52, and 55, the following piezoelectric materials can be used. (1) Piezoelectric crystal quartz (SiO ₂ ), Rochelle salt (RS: NaKC ₄ H)
₄ O ₆ · 4H ₂ O) tartaric ethylenediamine _{(ETD: C 6 H 14 N} 2 O 6)
, Potassium tartrate (DKT: K ₂ C ₄ H ₄ O ₆ .1 / 2H)
₂ O), dibasic ammonium phosphate (ADP: NH ₄ H ₂₎
PO ₄ ), a proovskite crystal (ex.
O ₃ , BaTiO ₃ , PLZT), tungsten bronze crystal (ex. Na _x WO ₃ [0.1 <x <0.2
8]), sodium barium niobate (Ba ₂ NaN
b ₅ O ₁₅ ), potassium lead niobate (Pb ₂ KNb)
₅ O ₁₅ ), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), sodium chlorate (NaClO ₃ ), tourmaline (Tourmalin)
e), sphalerite (ZuS), lithium sulfate (LiS)
O ₄ H ₂ O), lithium metagallate (LiGa
O ₂ ), lithium iodate (LiIO ₃ ), glycine sulfate (TGS), bismuth germanate (Bi ₁₂ G)
eO ₂₀ ), lithium germanate (LiGeO ₃ )
, Barium titanate, germanium (Ba ₂ Ge
₂ TiO ₃ ) and other crystals.

(2) Piezoelectric semiconductor wurtzite, BeO, ZnO, CdS, CdSe
, AlN. (3) Piezoelectric ceramics barium titanate (BaTiO ₃ ), lead zirconate titanate (PbTiO ₃ · PbZrO ₃ ),
Lead titanate (PbTiO ₃ ), lead barium niobate ((Ba—Pb) Nb ₂ O ₆ ). (4) The above (1) piezoelectric crystal, (2) piezoelectric semiconductor,
(3) Piezoelectric ceramics A material obtained by dispersing powder of a material in plastics and molding the same may be used. (5) piezoelectric polymer polyvinylidene fluoride _{PVDF (-CH 2 -CF 2 -)} n
, Polyvinylidene fluoride / PZT, rubber / PZT
, A copolymer of trifluoroethylene and vinylidene fluoride, a copolymer of vinylidene cyanide and vinyl acetate,
Polyvinylidene polyisocyanate and the like. After the above-mentioned piezoelectric materials are polarized, they may be processed and used as a piezoelectric material, or may be processed as a piezoelectric material and then subjected to a polarization treatment.

Overcoating of piezoelectric bodies The overcoating of the piezoelectric bodies 26 and 52 can be performed by the following methods (1) to (5). (1) Application of plastics Saturated polyester resin, polyamide resin, polyimide resin, acrylic resin, aramid resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyacetal, Thermoplastic resins such as polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, and styrene resin.

Epoxy resin, phenoxy resin, urethane resin, nylons, silicone resin, fluorosilicone resin, phenol resin, melamine resin
Thermosetting resin such as, xylene resin, alkyd resin, thermosetting acrylic resin. Polyvinylcarpazole,
Photoconductive resins such as polyvinylpyrene, polyvinylanthracene, and polyvinylol.

These can be used alone or in combination. In addition, engineered plastics such as liquid crystal polymers, and mixtures of plastics with powders and whiskers may be used. A photosensitive resin, a photoresist resin for a thick film, or the like can be used. Bakelite, fluororesin, glass / epoxy resin (glass filler mixed in epoxy) may be used. These are applied, dipped,
A known liquid application method such as a spray method may be used. Among the above, in particular, polyimide resin, aramid resin, epoxy resin, phenoxy resin, fluorosilicone resin,
Excellent effect of fluorine resin and glass / epoxy resin.

(2) Deposition of oxidized / nitrided / sulfided metal compounds etc. Metal oxide compounds (SiO ₂ , SiO, CrO, Al ₂ O ₃₎
), Metal nitride compounds (Si ₃ N ₄ , AlN, etc.), metal sulfide compounds (ZnS, etc.), or alloys thereof.
Coat by vacuum evaporation or sputtering. In addition, the above (1)
May be applied by vapor deposition, or parylene resin may be vapor deposited. In the above, Al ₂ O ₃ , S
The effect of i ₃ N ₄ is excellent.

(3) Application of Hydrocarbon Compounds Hydrocarbons, oxygen-containing hydrocarbons, sulfur-containing hydrocarbons and other Group IV element-containing hydrocarbons, nitrogen-containing hydrocarbons, silicon-containing hydrocarbons, and fluorine-containing hydrocarbons The halogen-containing hydrocarbon and the group III element-containing hydrocarbon are represented by P
-Coating by CVD (plasma CVD) and overcoating. Alternatively, PC-C
It may be applied by VD. 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 with the piezoelectric body. (4) Instead of applying the plastics of the above (1) on the surface of the piezoelectric body plate in a coating liquid state, the plastics forming part is replaced and impregnated under reduced pressure and molded. (5) Surface treatment of the surface of the piezoelectric plate with an ink-repellent solvent.

When the overcoat films formed by the methods described in the above (1) to (5) are compared, the following characteristics are observed (however, (3) is a case where the undercoat is present). Strength: Strong (2), (3)> (1), (4)> (5) Weak Smoothness: Good (1), (4)> (2), (3), (5) Poor adhesion ( (Including vibration resistance): Strong (1), (4)> (2), (3)> (5) Weak Durability (including ink resistance): Good (1), (4)> (2) , (3)> (5) Bad In addition, (5) is simple in processing, and can be used as post-processing of (1) to (4). In terms of cost, (1) and (4) are particularly inexpensive. The methods described in the above (1) to (5) may be used in appropriate combination according to the type of the piezoelectric material or the ink.

Materials for Top Plate and Substrate Materials that can be used for the non-piezoelectric material constituting the top plate 20 and the substrate 24 include the following (1) to (4). (1) Ceramics Al ₂ O ₃ , SiC, C, BaTiO ₃ , BiO ₃
3SnO ₂ , Pb (Zr _x , Ti _1-x ) O ₃ , ZnO
, SiO ₂ , (1-x) Pb (Zr _x , Ti _1-x ) O <sub>3
+ (X) La 2 O 3</sub> , Zn 1-x Mn x Fe 2 O 3, γ-F
_{e 2 O 3, Sr · 6Fe} 2 O 3, La 1-x Ca x CrO 3
, SnO ₂ , transition metal oxide, ZnO—Bi ₂ O ₃
, Semiconductor 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, PLZ
T, ThO ₂ , —CaO.nSiO ₂ , Ca
₅ (F, Cl) P ₃ O ₁₂ , TiO ₂ , K ₂ O · nAl ₂
O ₃ .

(2) Glasses Elemental glass = Si, Se, Te, As Hydrogen bond 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 nitrate 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 alkali silicate glass = Na ₂ O—CaO—SiO ₂ potassium lime glass = K ₂ O—CaO—SiO ₂ soda lime glass = Na ₂ O—CaO—SiO ₂ lead glass barium glass borosilicate Acid glass.

(3) Plastics Saturated polyester resin, polyamide resin, polyimide resin, aramid resin, acrylic resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyacetal , Polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, thermoplastic resin such as styrene resin.
Epoxy resin, urethane resin, nylon resin, silicone resin, phenol resin, melamine resin,
Thermosetting resins such as xylene resin, alkyd resin and thermosetting acrylic resin. Photoconductive resins such as polyvinylcarpazole, polyvinylpyrene, polyvinylanthracene, and polyvinylol.

The above (1) to (3) can be used alone or in combination. In addition, engineered plastics such as liquid crystal polymers, and mixtures of plastics with powders and whiskers may be used. A photosensitive resin, a photoresist resin for a thick film, and the like can also be used, and may be bakelite, a fluorine-based resin, or a glass / epoxy resin (glass filler mixed into epoxy).

(4) 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 and then processed into a top plate 20, or molded,
The shape of the top plate 20 may be molded from the beginning by using pattern etching, light curing, or the like.

[0072] As the materials of the partition wall 22, 48 of the partition wall, can be used as the listed below. (1) 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. Among the above, epoxy resin, phenoxy resin and fluorosilicone resin are preferably used.

(2) Saturated polyester resin, polyamide resin, acrylic resin, aramid resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyacetal, polyphenylene sulfide, polycarbonate , Vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, and styrene resin. Among the above, aramid resin, polyimide resin, polyamide resin, and ethylene-vinyl acetate resin are preferably used.

(3) Liquid crystal polymer (4) Photosensitive resin, photoresist resin for thick film (5) Rubber, synthetic rubber (6) Thin plate of nickel, stainless steel, titanium, tungsten, etc. Note that the above (1) to (5) ) May be used alone or in combination.

Comparing the superiority of the above-mentioned materials (1) to (6), (1) to (3) are almost the same, but excellent (1) to (3)>(4)>(6)> (5) Inferior characteristics are observed. In addition, the material thickness is 100μ
m or less, preferably 50 μm or less.

Adhesive Materials The following adhesives (1) to (4) can be used as adhesives for assembling the ink jet head 12. However, the adhesive used when bonding the piezoelectric body 26 to the substrate 24 needs to have conductivity. (1) Thermosetting resin adhesives such as epoxy resin, phenol resin, phenoxy resin, acrylic resin, furan resin, polyurethane resin, polyimide resin, and silicone resin. (2) Thermoplastic resin adhesives such as polyvinyl acetate, polyvinyl chloride, vinyl acetal, polyvinyl alcohol, and polyvinyl butyral. (3) UV curable resin adhesive. (4) Anaerobic curable adhesive.

[0077]

As is clear from the above description, in the ink jet recording apparatus of the present invention, each of the piezoelectric bodies is fixed to the substrate in a partially bonded state or is not bonded to the substrate at all. Crosstalk can be completely suppressed without vibration of one piezoelectric body propagating through the substrate to another piezoelectric body and interlockingly displacing. Therefore, it is possible to stably fly the ink droplet from each ink chamber,
Printing quality can be improved.

Further, since the piezoelectric body is partially bonded or not bonded at all, the displacement of the piezoelectric body when the partition is pushed up and the ink chamber is pressurized becomes large. This allows ink to fly to the extent possible, and can reduce driver cost. At the same time, since the displacement of the piezoelectric body is increased, the amount of displacement of the piezoelectric body can be adjusted by controlling the applied voltage by a voltage value, a pulse width, or a combination thereof. As a result, the diameter of the ink droplet flying from the ink chamber can be arbitrarily changed, and halftone reproduction of the color of the image drawn on the recording paper becomes possible.

Further, by fitting the piezoelectric body into the ink chamber concave portion so as to push the partition wall, or by forming the partition wall covering the ink chamber into a bulged shape and abutting the piezoelectric body, Ink jetting with high efficiency and excellent high-speed response can be achieved.

In addition, since the ink is not in direct contact with the piezoelectric body, the ink does not penetrate into the piezoelectric body to lower the resistance. Therefore, the displacement of the piezoelectric body does not decrease due to the decrease in the effective voltage, and as a result, the stability and reliability of the ink jet recording apparatus can be improved.

[Brief description of the drawings]

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

FIG. 2 is an overall perspective view of the inkjet head according to the first embodiment.

FIG. 3 is a cross-sectional view in a width direction of a main part of the inkjet head according to the first embodiment.

FIG. 4 is a longitudinal sectional view of a main part of the inkjet head according to the first embodiment.

FIG. 5 is a perspective view illustrating a manufacturing process of the inkjet head according to the first embodiment.

FIG. 6 is a perspective view illustrating a manufacturing process of the inkjet head according to the first embodiment.

FIG. 7 is a perspective view illustrating a manufacturing process of the inkjet head according to the first embodiment.

FIG. 8 is a perspective view illustrating a manufacturing process of the inkjet head according to the first embodiment.

FIG. 9 is a perspective view illustrating a manufacturing process of the inkjet head according to the first embodiment.

FIG. 10 is a diagram showing a pulse shape of a voltage applied to the piezoelectric body of the first embodiment.

FIG. 11 is a side view showing displacement of a piezoelectric body in a conventional inkjet head.

FIG. 12 is a side view showing displacement of a piezoelectric body in the ink jet head of the first embodiment.

FIG. 13 is a partially enlarged view of the section shown in FIG. 3;

FIG. 14 is a cross-sectional view in the width direction of a main part of an inkjet head according to a modification of the first embodiment.

FIG. 15 is a cross-sectional view in a width direction of a main part of an ink jet head according to another modification of the first embodiment.

FIG. 16 is a cross-sectional view in a width direction of a main part of the inkjet head according to the second embodiment.

FIG. 17 is an overall perspective view of a partition wall in the ink jet head of the second embodiment.

FIG. 18 is a cross-sectional view in a width direction of a main part of an inkjet head according to a modification of the second embodiment.

FIG. 19 is a side view of a laminated piezoelectric body applicable to the embodiment and its modified example.

FIG. 20 is a diagram illustrating a deformed state of the multilayer piezoelectric body of FIG. 19 that pressurizes the ink chamber.

FIG. 21 is a side view showing a deformed state of a laminated piezoelectric body that is not bonded to a substrate.

FIG. 22 is a plan view and a side view of a piezoelectric member formed in a comb shape.

FIG. 23 is a partial sectional view showing an example of a conventional inkjet head.

FIG. 24 is a partial cross-sectional view illustrating an example of a conventional inkjet head.

FIG. 25 is a partial cross-sectional view illustrating an example of a conventional inkjet head.

[Explanation of symbols]

12 inkjet head, 20 top plate, 21 recess, 22 partition wall, 23 ink chamber, 24 substrate, 26 ...
Piezoelectric, 27 ... individual electrode, 28 ... common electrode

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-71878 (JP, A) JP-A-5-318728 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/045 B41J 2/055

Claims (8)

(57) [Claims] 1. A non-piezoelectric member having a plurality of groove-shaped first concave portions serving as ink chambers, a substrate provided on the first concave portion forming surface of the non-piezoelectric member, and a position corresponding to the concave portion on the substrate. And a voltage for applying a voltage to the piezoelectric body in accordance with an image signal so that the piezoelectric body acts to pressurize and discharge the ink filled in the ink chamber. An ink jet recording apparatus comprising: a plurality of groove-shaped second recesses having a depth smaller than the height of the piezoelectric body corresponding to the plurality of first recesses of the non-piezoelectric member. And forming the piezoelectric body in each of the second concave portions, providing a partition wall that covers the first concave portion and forms an ink chamber between the first concave portion wall surface and a part of the piezoelectric body. (1) The partition wall is fitted into the recess. The first push to deflect into the recess inside the without fixing at least a portion of the piezoelectric to the substrate, an ink jet recording apparatus being characterized in that so as to act non-fixed portion of the piezoelectric body. 2. A non-piezoelectric member, in which a plurality of groove-shaped concave portions serving as ink chambers are formed, a substrate is provided on a concave portion forming surface of the non-piezoelectric member, and a plurality of piezoelectric members are provided on the substrate at positions corresponding to the concave portions. And an voltage applying means for applying a voltage to the piezoelectric body in accordance with an image signal so as to cause the piezoelectric body to act and pressurize and eject the ink filled in the ink chamber. In the ink jet recording apparatus, the ink chamber is formed between the wall of the concave portion by covering the concave portion or partitioning the inside of the concave portion, and a portion serving as one wall surface of the ink chamber swells to the piezoelectric body. Ink, wherein a partition wall is provided to abut, and at least a portion of the piezoelectric body is not fixed on the substrate, and an unfixed portion of the piezoelectric body is made to act. Jet recording apparatus. 3. The ink jet recording apparatus according to claim 1, wherein one end of the piezoelectric body is fixed to the substrate, and the other end is not fixed. 4. When a voltage is applied to the piezoelectric body, an unfixed portion of the piezoelectric body acts to move the partition wall forming the ink chamber away from the substrate or in a direction toward the substrate. 4. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is displaced. 5. The piezoelectric body is not fixed to the substrate at least in a region corresponding to the ink chamber, but is held and held between the partition and the substrate, and has a polarization direction inside the piezoelectric body. 2. An unfixed portion of the piezoelectric body is made to act on the ink chamber using a thickness direction vibration mode in which an electric field is formed in parallel to vibrate in the thickness direction of the piezoelectric body. 5. The ink jet recording apparatus according to any one of items 1 to 4. 6. The ink jet recording apparatus according to claim 1, wherein the piezoelectric body is a columnar body elongated in a direction along the ink chamber. 7. The ink jet recording apparatus according to claim 1, wherein each of the piezoelectric bodies is formed in a comb-like shape having a connected portion. 8. The non-piezoelectric member has a first convex portion defined between the first concave portions, while the substrate has a second convex portion defined between the second concave portions. , The first
8. The ink jet recording apparatus according to claim 1, wherein the convex portion and the second convex portion sandwich the partition.