JP3460722B2 - Ink jet recording head and ink jet recording apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element in which a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets is constituted by a vibrating plate, and a piezoelectric element is formed on the surface of the vibrating plate. The present invention relates to an inkjet recording head that ejects ink droplets by displacement.

[0002]

2. Description of the Related Art A part of a pressure generating chamber that communicates with a nozzle opening for ejecting ink droplets is composed of a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber to eject it from the nozzle opening. Two types of inkjet recording heads that eject ink droplets have been put into practical use: one that uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of a piezoelectric element, and one that uses a flexural vibration mode piezoelectric actuator. ing.

The former allows the volume of the pressure generating chamber to be changed by bringing the end face of the piezoelectric element into contact with the vibrating plate, and a head suitable for high-density printing can be manufactured. There is a problem in that the manufacturing process is complicated because a difficult process of matching the array pitch of the openings and cutting into comb teeth or a work of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required.

On the other hand, in the latter, the piezoelectric element can be formed on the vibration plate by a relatively simple process of sticking a green sheet of a piezoelectric material in conformity with the shape of the pressure generating chamber and firing it. However, due to the use of flexural vibration, a certain area is required, and there is a problem that high-density arrangement is difficult.

On the other hand, in order to eliminate the disadvantage of the latter recording head, a uniform piezoelectric material layer is formed on the entire surface of the diaphragm by a film forming technique, and this piezoelectric material layer is formed into a pressure generating chamber by a lithography method. There has been proposed a piezoelectric element that is divided into corresponding shapes and is formed independently of each pressure generating chamber (for example, see Patent Document 1).

According to this, the work of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only the piezoelectric element can be built by a precise and simple method such as the lithography method, but also the thickness of the piezoelectric actuator can be reduced. It has the advantage that it can be made thin and can be driven at high speed. In this case,
By providing at least only the upper electrode for each pressure generating chamber while leaving the piezoelectric material layer provided on the entire surface of the vibration plate, the piezoelectric actuator corresponding to each pressure generating chamber can be driven.

In such an ink jet recording head, generally, a reservoir serving as a common ink chamber of each pressure generating chamber is formed by stacking a plurality of substrates, and each pressure generating chamber is formed from this reservoir. Ink is supplied to. Further, this reservoir is provided with a compliance part for absorbing a pressure change when the piezoelectric element is driven in order to keep the internal pressure of the reservoir constant.

[0008]

[Patent Document 1] Japanese Unexamined Patent Publication No. 5-286131 (first to first)
(Fig. 4)

[0009]

However, the number of substrates used to form the reservoir is large, and in particular, the number of substrates to be laminated to form the compliance portion is large, resulting in high material cost and assembly cost. There is.

Further, when silicon is used for the substrate that defines the pressure generating chamber, it is difficult to bond it at high temperature due to the difference in thermal expansion coefficient with other substrates, and there is a problem that the number of assembling steps is increased. is there.

In view of the above circumstances, it is an object of the present invention to provide an ink jet recording head and an ink jet recording apparatus which have a simplified structure and which reduce the manufacturing cost.

[0012]

A first aspect of the present invention for solving the above-mentioned problems is to provide a nozzle forming member having a plurality of nozzle openings for ejecting ink, the nozzle forming member being joined to the nozzle forming member, and the nozzle opening. And a flow path forming substrate defining a pressure generating chamber communicating with the flow path forming substrate and a surface of the flow path forming substrate that is opposite to the surface on which the nozzle forming member is joined. In an ink jet recording head including a piezoelectric element to be generated, ink is supplied to each pressure generating chamber in communication with the pressure generating chamber on the surface of the flow path forming substrate on which the piezoelectric element is formed. A reservoir forming substrate provided with a reservoir portion forming at least a part of the reservoir penetrating in the thickness direction and a compliance substrate including a flexible member having flexibility are laminated, By forming the reservoir substantially with the synthetic substrate and the reservoir forming substrate and joining the flexible member so as to seal the opening of the reservoir portion, the flow passage forming substrate side of the reservoir forming substrate The ink jet recording head is characterized in that a flexible portion is formed in a region facing the reservoir portion on a surface opposite to the surface.

In the first aspect, the number of stacked substrates for forming the reservoir can be reduced, and the structure can be simplified.

A second aspect of the present invention is the ink jet recording head according to the first aspect, characterized in that the flexible member is made of a metal or ceramic thin film.

In the second aspect, the flexible portion can be easily formed by forming the thin film on the flow path forming substrate.

A third aspect of the present invention is the ink jet recording head according to the first aspect, characterized in that the flexible member is made of a resin material.

In the third aspect, since the flexible portion is made of the resin member, it can be easily formed.

According to a fourth aspect of the present invention, in any one of the first to third aspects, another substrate having a through hole is joined to the flexible member at least in a region facing the flexible portion. The inkjet recording head is characterized by being provided.

In the fourth aspect, the strength of the portion other than the flexible portion is improved and the durability of the head is improved.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the flow path forming substrate communicates with the reservoir portion of the reservoir forming substrate and the reservoir portion and the reservoir portion together with the reservoir portion. An ink jet recording head is characterized in that it has a communication section that constitutes a section.

In the fifth aspect, the reservoir is composed of the reservoir portion and the communicating portion, and the reservoir having a relatively large volume can be easily formed.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the reservoir and each pressure generating chamber are respectively provided via an ink supply passage having a narrower passage than the reservoir. The inkjet recording head is characterized by being communicated.

In the sixth aspect, since the ink is supplied from the reservoir to the pressure generating chamber through the ink supply passage having a relatively narrow passage, the amount of bubbles mixed in the ink can be suppressed.

In a seventh aspect of the present invention according to any one of the first to sixth aspects, ink is introduced into the reservoir portion of the reservoir forming substrate so as to communicate with the outside and supply ink to the reservoir. An ink jet recording head is characterized in that its mouth is communicated.

In the seventh aspect, ink is supplied from the ink introduction port to the reservoir.

In an eighth aspect of the present invention according to any one of the first to seventh aspects, a state in which the reservoir forming substrate secures a space in a region facing the piezoelectric element, the space not hindering the movement thereof. The inkjet recording head is characterized by having a piezoelectric element holding portion capable of sealing the space.

In the eighth aspect, the piezoelectric element is hermetically sealed in the piezoelectric element holding portion, and the destruction of the piezoelectric element due to the external environment is prevented.

According to a ninth aspect of the present invention, in the eighth aspect, the piezoelectric element holding portion is divided by a partition wall for each piezoelectric element, and the partition wall is joined to the flow path forming substrate. An inkjet recording head characterized by the above.

In the ninth aspect, the rigidity of the peripheral wall defining the pressure generating chamber is increased and the peripheral wall is prevented from collapsing when the piezoelectric element is driven.

A tenth aspect of the present invention is an ink jet recording apparatus including the ink jet recording head according to any one of the first to ninth aspects.

In the tenth aspect, it is possible to realize an ink jet recording apparatus with a simplified manufacturing structure and a reduced manufacturing cost.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a sectional view of FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation (110) in this embodiment. The flow path forming substrate 10 is usually 150 to 3
A thickness of about 00 μm is used, preferably 18
The thickness is preferably about 0 to 280 μm, more preferably about 220 μm. This is because the array density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is provided with an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide formed by thermal oxidation in advance.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on the silicon single crystal substrate,
Pressure generating chambers 12 partitioned by a plurality of partition walls 11 are arranged side by side in the width direction, and on the outer side in the longitudinal direction, the pressure generating chambers 12 communicate with a reservoir portion of a reservoir forming substrate, which will be described later, and a common ink chamber of each pressure generating chamber 12. A communication portion 13 that forms a part of the reservoir 100 is formed, and is communicated with one end portion in the longitudinal direction of each pressure generation chamber 12 via an ink supply passage 14, respectively.

In the anisotropic etching, when a silicon single crystal substrate is dipped in an alkaline solution such as KOH, it is gradually eroded to form a first (111) plane perpendicular to the (110) plane and the first (111) plane. Of the second (1) which makes an angle of about 70 degrees with the (111) plane of
The (11) plane appears, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
It is performed by utilizing the property of being 80.
By such anisotropic etching, two first (11
Precision machining can be performed on the basis of the depth machining of the parallelogram shape formed by the 1) plane and the two diagonal second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided in the flow path forming substrate 1
It is formed by etching through almost 0 to reach the elastic film 50. Here, the elastic film 50 is
The amount of the alkaline solution that etches the silicon single crystal substrate is extremely small. Further, each ink supply passage 14 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and keeps the flow resistance of the ink flowing into the pressure generation chamber 12 constant. That is, the ink supply path 14 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). The half etching is performed by adjusting the etching time.

On the opening surface side of the flow path forming substrate 10,
A nozzle plate 16 having a nozzle opening 15 communicating with the pressure supply chamber 12 on the side opposite to the ink supply passage 14 is fixed via an adhesive or a heat-welding film. The nozzle plate 16 has a thickness of, for example, 0.1 to 1
mm, a coefficient of linear expansion of 300 ° C. or less, for example, 2.5 to
4.5 [× 10 ⁻⁶ / ° C.] glass-ceramic,
Or made of non-rust steel. The nozzle plate 16 entirely covers one surface of the flow path forming substrate 10 with one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. Further, the nozzle plate 16 is used as the flow path forming substrate 1
It may be made of a material whose coefficient of thermal expansion is substantially the same as that of the material. In this case, since the flow path forming substrate 10 and the nozzle plate 16 are deformed substantially by the heat, they can be easily joined by using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12 that applies the ink droplet ejection pressure to the ink and the size of the nozzle opening 15 that ejects the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, it is necessary to accurately form the nozzle openings 15 with a groove width of several tens of μm.

On the other hand, a thickness of, for example, about 0.2 μm is formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10.
The lower electrode film 60, the piezoelectric film 70 having a thickness of, for example, about 1 μm, and the upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated and formed in a process described later to form the piezoelectric element 30.
Configures 0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. In general, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Further, here, a portion which is composed of one of the patterned electrodes and the piezoelectric film 70 and in which piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is the common electrode of the piezoelectric element 300 and the upper electrode film 80 is the individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed due to the drive circuit and wiring. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also here
The piezoelectric element 300 and the vibration plate that is displaced by the driving of the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In the example described above, the elastic film 50 and the lower electrode film 6
Although 0 acts as a diaphragm, the lower electrode film may also serve as the elastic film.

Further, the piezoelectric element 300 of the flow path forming substrate 10
A reservoir forming substrate 20 having a reservoir portion 21 forming at least a part of the reservoir 100 is bonded to the side. In the present embodiment, the reservoir portion 21 penetrates the reservoir forming substrate 20 in the thickness direction, and the pressure generating chamber 12
Is formed across the width direction of the. Then, as described above, the reservoir 100, which is connected to the communication portion 13 of the flow path forming substrate 10 and serves as a common ink chamber for the pressure generating chambers 12, is configured.

As the reservoir forming substrate 20, it is preferable to use a material having substantially the same coefficient of thermal expansion as that of the passage forming substrate 10 such as glass or a ceramic material. It was formed using a silicon single crystal substrate of the same material. As a result, as in the case of the nozzle plate 16 described above, the two can be reliably bonded even if they are bonded at a high temperature using a thermosetting adhesive. Therefore, the manufacturing process can be simplified.

Further, the reservoir forming substrate 20 includes
A compliance substrate 30 including a sealing film 31 and a fixing plate 32 is joined. Here, the sealing film 31 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 31 seals one surface of the reservoir portion 21. It has been stopped. Further, the fixing plate 32 is made of a hard material such as metal (for example, stainless steel having a thickness of 30 μm (SU
S) and the like). The reservoir 10 of this fixed plate 32
Since the region facing 0 is the opening 33 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only by the sealing film 31 having flexibility, and the internal pressure changes. The flexible portion 22 is deformable by.

An ink inlet 25 for supplying ink to the reservoir 100 is formed on the compliance substrate 30 outside the central portion in the longitudinal direction of the reservoir 100. Further, the reservoir forming substrate 20 is provided with an ink introducing passage 26 that connects the ink introducing port 25 and the side wall of the reservoir 100. In addition, in the present embodiment, the ink is supplied to the reservoir 100 by one ink introduction port 25 and the ink introduction passage 26, but the present invention is not limited to this, and for example, according to a desired ink supply amount, A plurality of ink introduction ports and ink introduction passages may be provided, or the opening area of the ink introduction port may be increased to enlarge the ink flow passage.

Normally, from the ink inlet 25 to the reservoir 10
When ink is supplied to 0, a pressure change occurs in the reservoir 100 due to, for example, the flow of ink when the piezoelectric element 300 is driven, ambient heat, or the like. However, as described above, one surface of the reservoir 100 has the sealing film 3
Since the flexible portion 22 is sealed by only 1 to form the flexible portion 22, the flexible portion 22 flexibly deforms and absorbs the pressure change. Therefore, the inside of the reservoir 100 is always kept at a constant pressure. The other portions are held by the fixing plate 32 with sufficient strength. Further, in the present embodiment, the number of substrates constituting the reservoir 100 and the like can be reduced, so that the material cost, the assembly cost and the like can be reduced.

On the other hand, the piezoelectric element 3 of the reservoir forming substrate 20
In a region facing 00, a piezoelectric element holding portion 24 capable of sealing the space in a state where the movement of the piezoelectric element 300 is not obstructed is provided, and at least the piezoelectric active portion 320 of the piezoelectric element 300 is provided. Are sealed in the piezoelectric element holding portion 24. In the present embodiment, the piezoelectric element holding portion 24 includes the plurality of piezoelectric elements 3 arranged side by side in the width direction.
It is formed in a size that covers 00.

As described above, the reservoir forming substrate 20 constitutes the reservoir 100 and also serves as a cap member for isolating the piezoelectric element 300 from the external environment, so that the piezoelectric element 300 is not damaged by the external environment such as moisture. Can be prevented. In addition, in the present embodiment, the piezoelectric element holding portion 2
Although only the inside of 4 is sealed, the inside of the piezoelectric element holding portion 24 is kept at a low humidity by, for example, evacuating the space inside the piezoelectric element holding portion 24 or by setting a nitrogen or argon atmosphere or the like. The piezoelectric element 30
It is possible to more surely prevent the destruction of 0.

Further, in this embodiment, the piezoelectric film 70 and the upper electrode film 80 of the piezoelectric element 300 thus sealed by the piezoelectric element holding portion 24 are flow paths from one longitudinal end of the pressure generating chamber 12. The exposed portion 10 extends on the formation substrate 10 to the outside of the reservoir formation substrate 20, and the surface of the flow path formation substrate 10 on the side of the junction with the reservoir formation substrate is exposed.
On a, for example, external wiring 4 such as a flexible cable
It is connected to 0. That is, by extending the wiring from the piezoelectric element 300 to the outside of the reservoir forming substrate 20, the piezoelectric element 300 and the external wiring can be easily connected.

The ink jet recording head of this embodiment as described above takes in ink from the ink introduction port 25 connected to an external ink supply means (not shown), and stores it in the reservoir 1.
00 to the nozzle opening 15, the inside is filled with ink, and then each lower electrode film 60 corresponding to the pressure generating chamber 12 is generated according to a recording signal from an external drive circuit (not shown).
By applying a voltage between the upper electrode film 80 and the upper electrode film 80 to bend and deform the elastic film 50, the lower electrode film 60, and the piezoelectric film 70, the pressure in each pressure generating chamber 12 increases and the nozzle opening 1
Ink droplets are ejected from 5.

In this embodiment, the piezoelectric element holding portion 24 of the reservoir forming substrate 20 is formed so as to cover all the piezoelectric elements 300 juxtaposed in the width direction, but the present invention is not limited to this. For example, as shown in FIG. 3, the piezoelectric element holding portion 24 is made into an independent piezoelectric element holding portion 24A for each piezoelectric element 300 by the partition wall 27, and the piezoelectric element 300 is sealed in each piezoelectric element holding portion 24A. You may As a result, the partition walls 27 are respectively joined to the portions of the flow path forming substrate 10 corresponding to the side walls 12a of the pressure generating chambers 12, and the rigidity of the peripheral wall of the pressure generating chambers 12 is improved, and the piezoelectric element is formed. It is possible to prevent the peripheral wall from collapsing when the 300 is driven. Needless to say, even with such a configuration, it is possible to prevent the piezoelectric element 300 from being broken, as in the above-described embodiment.

In this embodiment, the flow path forming substrate 10 is also used.
Is formed to be larger than the reservoir forming substrate 20 and the piezoelectric element 300 and the external wiring 40 are connected on the exposed portion 10a of the flow passage forming substrate 10, but the present invention is not limited to this. 4, the reservoir forming substrate 20
Is formed to be larger than the flow path forming substrate 10 to form an exposed portion 20a that exposes the surface of the reservoir forming substrate 20 on the side where the flow path forming substrate 10 is bonded, and on this exposed portion 20a, the piezoelectric element 300 and the external wiring You may make it connect with.

Further, in this embodiment, the flow path forming substrate 1
Although the communication portion 13 forming a part of the reservoir 100 is provided on the end side of the pressure generation chamber 12 of 0 opposite to the nozzle opening 15 through the ink supply passage 14, the invention is not limited to this. For example, as shown in FIG. 5, the reservoir 100 is basically configured only by the reservoir portion 21 of the reservoir forming substrate 20, and each pressure generating chamber 1 is formed in the flow passage forming substrate 10.
2 and the reservoir 100 may be communicated with each other through the communication passage 18 having a narrower flow passage than the reservoir 100. With such a configuration, since the flow velocity of the ink is maintained when the ink is supplied to the pressure generating chamber 12, it is possible to prevent the inclusion of air bubbles and perform good ink ejection.

(Second Embodiment) FIG. 6 is a plan view and a sectional view of an ink jet recording head according to a second embodiment.

In this embodiment, as shown in FIG. 6, the compliance substrate 30 is not provided on a part of the reservoir forming substrate 20 opposite to the reservoir 100, and the surface of the reservoir forming substrate 20 is exposed. Has been done. And
Piezoelectric element 3 extended to the outside of the reservoir forming substrate 20
The wiring 28 is extended from the upper electrode film 80 of 00 to the surface of the reservoir forming substrate 20 by wire bonding, and the end portion of the extended wiring 28 connects the piezoelectric element 300 and the external wiring 40 to the mounting portion 90. And Further, the second embodiment is the same as the first embodiment except that the outer side thereof is molded with an insulating member 95 such as epoxy for electrical insulation.

Here, as in the conventional case, the flow path forming substrate 10
When the piezoelectric element 300 and the external wiring 40 are connected on the exposed portion 10a, the width of the exposed portion 10a is about 2.2.
It requires about 3 mm, and the size of the head becomes slightly larger. On the other hand, in the present embodiment, the wiring 28 is extended from the exposed portion 10a of the flow path forming substrate 10 to the exposed portion 20a of the reservoir forming substrate 20 by wire bonding and is connected to the external wiring 40. Therefore, the width of the exposed portion 10a of the flow path forming substrate 10 can be set to about 0.2 mm, and the size of the recording head can be further reduced. Further, of course, even with such a configuration, the same effect as that of the first embodiment can be obtained.

(Third Embodiment) FIG. 7 is a plan view and a sectional view of an ink jet recording head according to a third embodiment.

This embodiment is an example in which a through groove is provided in the reservoir forming substrate 20, and the piezoelectric element 300 and the external wiring are connected through this through groove. More specifically, as shown in FIG. 7, in the present embodiment, the piezoelectric film 70 and the upper electrode film 80 of the piezoelectric element 300 are extended to the circumferential wall of the pressure generating chamber 12 on the nozzle opening 15 side, and the flow path is formed. It is sandwiched between the formation substrate 10 and the reservoir formation substrate 20. Further, similarly to the second embodiment, a part of the bonding surface of the reservoir forming substrate 20 with the compliance substrate 30 is an exposed portion 20b whose surface is exposed. The exposed portion 20b corresponds to the exposed portion 20b and the piezoelectric element 300 is provided. In the area facing the upper electrode film 80,
A through groove 35 extending across the row of the pressure generating chambers 12 is formed. Then, the wiring 28 is extended from the upper electrode film 80 of each piezoelectric element 300 through the through groove 35 onto the surface of the reservoir forming substrate 20 by wire bonding.
The end portion of the wiring 28 serves as a mounting portion 90 that connects the piezoelectric element 300 and the external wiring 40 such as a flexible cable.

In such a structure, the wiring 28 extends through the through groove 35, and therefore, the above-described flow path forming substrate 10 is formed.
Alternatively, it is not necessary to provide the exposed portions 10a and 20a of the reservoir forming substrate 20, and the head can be made smaller.

Although the through groove 35 is formed in a groove shape over the rows of the pressure generating chambers 12 in the present embodiment, it is not limited to this and, for example, is independent for each piezoelectric element 300. You may make it provide a through hole.

Further, in the above-described embodiment, the wiring 28 is extended from the upper electrode film 80 by wire bonding, but the invention is not limited to this. For example, as shown in FIG. ) Through the conductive thin film 3
The wiring 28 </ b> A may be formed by forming a film on the inner peripheral surface of 5 and the upper surface of the compliance substrate 30 and patterning this conductive thin film for each piezoelectric element 300.

(Fourth Embodiment) FIG. 9 is a plan view and a sectional view of an ink jet recording head according to a fourth embodiment.

In this embodiment, as shown in FIG. 9, the flow path forming substrate 10 is provided with two rows in which the pressure generating chambers 12 are arranged side by side in the width direction so that the ends on the nozzle opening 15 side face each other. Piezoelectric elements 300 are formed in the regions corresponding to the respective pressure generating chambers 12. Further, a reservoir 100 is provided outside the pressure generating chambers 12 in the longitudinal direction for each row of the pressure generating chambers, and an ink introducing port 25 and an ink introducing passage 26 are connected to these reservoirs 100, respectively. ing. The structures of the reservoir, the ink inlet, and the like are the same as those in the above-described embodiment.

Further, the piezoelectric elements 300 are respectively extended from the region facing the pressure generating chamber 12 to the peripheral wall on the reservoir 100 side, and the flow path forming substrate 10 and the reservoir forming substrate 2 are provided.
It is sandwiched between 0 and. In the region facing the upper electrode film 80 of the piezoelectric element 300, the through groove 35A is provided for each row of the pressure generating chambers 12 as in the above-described embodiment. In addition, for example, the piezoelectric element 300 is provided on the reservoir forming substrate 20 in a region corresponding to the row between the pressure generating chambers 12.
A drive circuit 110 for driving the is mounted. The drive circuit 110 may be a circuit board or a semiconductor integrated circuit (IC) including the drive circuit. Then, the upper electrode film 80 of each piezoelectric element 300 and the drive circuit 110 are connected to each other by the wiring 28 extended by wire bonding or the like via the through groove 35A. Further, wiring for supplying a signal to the driving circuit 110 is provided on the reservoir substrate 20, one end of this wiring is connected to the driving circuit 110, and the other end is connected to the external wiring 40. It is 90.

With such a structure, the head can be downsized as in the third embodiment. Further, in the present embodiment, since the through groove 35A is provided on the reservoir 100 side, the piezoelectric element 300 and the driving means 110 and the like can be more efficiently connected between the plurality of rows of the pressure generating chambers 12. it can.

In this embodiment, the drive means 110 is provided on the reservoir forming substrate 20, but the present invention is not limited to this, and for example, as in the first embodiment, the reservoir forming substrate 2 is provided.
It goes without saying that the wiring extended from the piezoelectric element 300 and the external wiring such as the flexible cable may be connected on the exposed portion 10a of 0.

(Fifth Embodiment) FIG. 10 is a cross-sectional view of an essential part of an ink jet recording head according to a fifth embodiment.

The present embodiment is an example in which the compliance substrate 30A composed of one member is provided on the flow path forming substrate 10. In the present embodiment, as shown in FIG. 10, a portion of the region facing the reservoir 100 in the thickness direction is removed to form a flexible portion 22A having flexibility, and a penetrating portion that serves as an ink introduction port 25 is provided on the outside thereof. The same as Embodiment 1 except that the holes are formed. The material of such a compliance substrate 30A has flexibility, for example, fluororesin,
It is preferable to use a resin material such as silicone resin or silicone rubber, whereby the compliance substrate 3
OA can be easily formed.

The method of manufacturing the compliance substrate 30A is not particularly limited, but, for example, after forming a resin layer of a predetermined thickness on the silicon single crystal substrate forming the reservoir forming substrate 20, the reservoir forming substrate 20 is formed. It can be formed by forming the reservoir 100 and the like by etching or the like, and further by etching a part of the region of the resin layer facing the reservoir 100 in the thickness direction.

In this embodiment, the compliance substrate 30A is made of a resin material. However, the present invention is not limited to this. For example, as shown in FIG. You may make it comprised by the metal or ceramic thin film of about 10 micrometers. In this case, the region facing the reservoir 100 can be the flexible portion 22B having flexibility without removing a part in the thickness direction. Therefore, the head can be manufactured more easily.

(Sixth Embodiment) FIG. 12 is a plan view and a sectional view of an ink jet recording head according to a sixth embodiment.

In the present embodiment, as shown in FIG. 12, the piezoelectric element is provided in a portion of the reservoir forming substrate 20 facing the piezoelectric element holding portion 24 corresponding to the piezoelectric element 300 in the column direction of the pressure generating chambers 12. The third embodiment is the same as the first embodiment except that the detection through hole 29 for detecting the displacement of the 300 is provided.

In such a structure, the reservoir forming substrate 2
Before the compliance substrate 30 is bonded onto the surface 0, the displacement of the piezoelectric element 300 can be checked by using, for example, a laser. Therefore, a defect of the piezoelectric element 300 can be found before the head is completed, and the manufacturing efficiency can be improved. In addition, this detection through hole 29
Is sealed by the compliance substrate 30, so that the piezoelectric element holding portion 24 can be held in a sealed state as in the first embodiment.

The size of such a through hole 29 for detection is
It is not particularly limited as long as it is formed at least in a region facing the piezoelectric element 300. Therefore, in this embodiment, the pressure generating chambers 12 are provided in a groove shape in the column direction, but may be round holes for each piezoelectric element 300, for example.
Alternatively, the entire piezoelectric element holding portion may be a through hole.

In this embodiment, the through hole 29 for detection is used.
Is sealed with the compliance substrate 30, but the invention is not limited to this. For example, as shown in FIG. 13, the detection through hole 29 is sealed only with the sealing film 31 having flexibility, that is, the detection is performed. The flexible plate 24a may be formed by removing the fixing plate 32 in the region facing the through hole 29 for use. As a result, when a pressure change occurs in the piezoelectric element holding portion 24, the flexible portion 24
The deformation of “a” absorbs the pressure change, so that the inside of the piezoelectric element holding portion 24 can be constantly maintained at a constant pressure.

Further, the flexible portion 24a of the piezoelectric element holding portion 24
The sealing film 31 to be formed may be formed of, for example, a light-transmissive member such as acrylic resin, and thereby the displacement can be detected in a state where the piezoelectric element 300 is sealed in the piezoelectric element holding portion 24. it can. That is, the piezoelectric element 300 can be constantly inspected.

(Other Embodiments) Although the respective embodiments of the present invention have been described above, the basic structure of the ink jet recording head is not limited to the above.

For example, in the above-described embodiment, the nozzle plate 16 as the nozzle forming member having the nozzle opening 15 is bonded to one surface of the flow path forming substrate 10, but the present invention is not limited to this, and for example, The nozzle forming member may have a multi-layer structure including another substrate having a nozzle communication hole that communicates the nozzle opening and the pressure generating chamber.

In each of the above-described embodiments, the thin film type ink jet recording head manufactured by applying the film formation and the lithographic process is taken as an example. However, the present invention is not limited to this and, for example, green The present invention can also be applied to a thick film type ink jet recording head formed by a method such as attaching a sheet.

Further, the ink jet recording head of each of these embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. 14
FIG. 3 is a schematic view showing an example of the inkjet recording apparatus.

As shown in FIG. 14, the recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B forming an ink supply unit are detachably provided, and a carriage 3 having the recording head units 1A and 1B mounted thereon is provided on a carriage shaft 5 attached to an apparatus main body 4 so as to be axially movable. There is. The recording head units 1A and 1B are, for example,
The black ink composition and the color ink composition are respectively discharged.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the carriage 3 having the recording head units 1A and 1B mounted thereon extends along the carriage shaft 5. Be moved. On the other hand, a platen 8 is provided on the apparatus body 4 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a feed roller (not shown), is wound around the platen 8. It is designed to be transported.

[0083]

As described above, according to the present invention, the reservoir forming substrate forming at least a part of the reservoir is bonded on the flow passage forming substrate to form the reservoir. It can be simplified, the number of manufacturing steps can be reduced, and the manufacturing cost can be improved. Further, since the reservoir forming substrate also serves as a cap member that shields the piezoelectric element from the outside, it is possible to prevent the piezoelectric element from being damaged due to the external environment, and it is possible to improve the durability. Furthermore, by connecting the piezoelectric element and the external wiring on the reservoir forming substrate, it is possible to reduce the size of the head.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to a first embodiment of the invention.

2A and 2B are a plan view and a sectional view of the ink jet recording head according to the first embodiment of the invention.

3A and 3B are a plan view and a cross-sectional view showing a modified example of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view showing a modified example of the ink jet recording head according to the first embodiment of the invention.

5A and 5B are a plan view and a cross-sectional view showing a modified example of the ink jet recording head according to the first embodiment of the invention.

6A and 6B are a plan view and a side view of an ink jet recording head according to a second embodiment of the invention.

FIG. 7 is a plan view and a cross-sectional view of an ink jet recording head according to a third embodiment of the invention.

FIG. 8 is a plan view and a cross-sectional view showing a modified example of the ink jet recording head according to the third embodiment of the invention.

9A and 9B are a plan view and a sectional view of an ink jet recording head according to a fourth embodiment of the invention.

FIG. 10 is a cross-sectional view of essential parts of an ink jet recording head according to a fifth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a modified example of the ink jet recording head according to the fifth embodiment of the invention.

FIG. 12 is a plan view and a sectional view of an ink jet recording head according to a sixth embodiment of the invention.

FIG. 13 is a sectional view showing a modified example of the ink jet recording head according to the sixth embodiment of the invention.

FIG. 14 is a schematic diagram of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

10 Flow path forming substrate 12 Pressure generation chamber 13 Communication 14 Ink supply path 15 nozzle opening 16 nozzle plate 20 Reservoir forming substrate 21 Reservoir section 22 Flexible part 24 Piezoelectric element holder 30, 30A compliance board 31 sealing film 32 fixed plate 60 Lower electrode film 70 Piezoelectric film 80 Upper electrode film 100 reservoir 300 Piezoelectric element

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-314863 (JP, A) JP-A-7-156396 (JP, A) JP-A-8-169111 (JP, A) JP-A-9- 123449 (JP, A) JP-A-3-187756 (JP, A) JP-A-63-149159 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2 / 055 B41J 2/16

Claims (10)

(57) [Claims] 1. A nozzle forming member having a plurality of nozzle openings for ejecting ink, and a flow path forming substrate which is joined to the nozzle forming member and defines pressure generating chambers communicating with the nozzle openings, respectively. An ink jet recording head, comprising: a piezoelectric element that is provided on a surface of the flow path forming substrate opposite to a surface on which the nozzle forming member is joined and that causes a pressure change in the pressure generating chamber. On the surface of the substrate on which the piezoelectric element is formed, a reservoir portion that communicates with the pressure generating chambers and forms at least a part of a reservoir that supplies ink to the pressure generating chambers penetrates in the thickness direction. The provided reservoir forming substrate and the compliance substrate including a flexible member having flexibility are stacked, and the flow passage forming substrate and the reservoir forming substrate substantially form the reservoir. And a region facing the reservoir portion on the surface of the reservoir forming substrate opposite to the flow passage forming substrate side by joining the flexible member so as to seal the opening of the reservoir portion. An ink jet recording head, characterized in that a flexible portion is formed on the. 2. The flexible member according to claim 1,
An inkjet recording head comprising a thin film of metal or ceramic. 3. The flexible member according to claim 1, wherein
An ink jet recording head, which is made of a resin material. 4. The flexible substrate according to claim 1, wherein another substrate having a through hole is bonded to at least the region facing the flexible portion. Inkjet recording head. 5. The flow passage forming substrate according to claim 1, further comprising a communicating portion that communicates with the reservoir portion of the reservoir forming substrate and forms a part of the reservoir together with the reservoir portion. An ink jet recording head characterized by the above. 6. The ink storage device according to claim 1, wherein the reservoir and each pressure generating chamber are communicated with each other via an ink supply passage having a relatively smaller passage than the reservoir. Inkjet recording head. 7. The ink introducing port according to claim 1, wherein the reservoir portion of the reservoir forming substrate is communicated with an ink introduction port for communicating with the outside to supply ink to the reservoir. Characteristic ink jet recording head. 8. The piezoelectric device according to claim 1, wherein the reservoir forming substrate is capable of sealing the space in a region facing the piezoelectric element in a state where a space that does not hinder its movement is secured. An ink jet recording head having an element holding portion. 9. The ink jet recording according to claim 8, wherein the piezoelectric element holding portion is partitioned by a partition wall for each piezoelectric element, and the partition wall is bonded to the flow path forming substrate. head. 10. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.