JP2002067305A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a recording head smaller in size. SOLUTION: By selectively removing an adhesive layer 3 of an elastic film 31, thickness of a compliance part 31B sealing one side opening of a common ink chamber 16 is made thinner than thickness of a sealing part 31A sealing one side opening of a pressurizing chamber 18, and hence the compliance is heightened.

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 head suitably used for an ink jet recording apparatus such as a printer or a plotter.

[0002]

2. Description of the Related Art A conventional ink jet recording head, for example, a recording head using a piezoelectric vibrator as an electromechanical transducer, includes a nozzle plate having a plurality of nozzle openings formed in a row, a common ink chamber and a pressure chamber. A flow path forming substrate formed with an ink flow path that communicates with the nozzle opening via a pressure chamber and an elastic plate having an elastic film that seals one opening surface of the common ink chamber. There is a configuration in which a channel unit is configured by joining in a stacked state, and the channel unit is joined to a case. The flow path forming substrate is, for example, manufactured by etching a silicon wafer, and a stainless steel nozzle plate is joined to one surface of the flow path forming substrate,
An elastic plate is joined to the other surface. The elastic plate is made of, for example, a composite plate material in which a two-layer elastic film composed of an adhesive layer and a resin film is supported by a stainless steel support plate. It also serves as a chamber sealing part and a common ink chamber compliance part.

In this ink jet recording head, a series of ink flow paths from a common ink chamber to a nozzle opening via a pressure chamber is formed for each nozzle opening. When an ink droplet is ejected from the nozzle opening, the volume of the pressure chamber is varied by deforming the elastic film by the piezoelectric vibrator, and the pressure in the pressure chamber is increased or decreased.

[0004]

By the way, in the ink jet recording head having the above structure, a plurality of ink supply ports face the common ink chamber. For this reason, when the pressure chamber is contracted at the time of discharging the ink droplet, a pressure wave (ink jet) is generated from the ink supply port toward the common ink chamber. Here, an ink supply port that communicates with each pressure chamber communicates with the common ink chamber. As a result, if a pressure wave emitted from the ink supply port acts on another pressure chamber through another ink supply port, ejection of ink droplets by the pressure chamber becomes unstable.

In order to prevent such a problem, it is preferable to set a large compliance for the common ink chamber. On the other hand, from the viewpoint of improving the response of ink droplet ejection, it is preferable to set the compliance of the pressure chamber to be small. However, in the conventional elastic film, the sealing portion of the pressure chamber and the compliance portion of the common ink chamber are formed with the same thickness, and the thickness of the elastic film is defined according to the response of ink droplet ejection. ing. For this reason, in order to obtain necessary compliance with respect to the common ink chamber, it is necessary to make the area of the compliance portion in the elastic film sufficiently large. There was a problem that miniaturization was hindered.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to set the compliance of the common ink chamber large while maintaining good responsiveness of ink droplet ejection, and to reduce the size of the common ink chamber. Accordingly, it is an object of the present invention to provide an ink jet recording head capable of promoting downsizing of the recording head.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object. According to the first aspect of the present invention, there is provided a series of inks communicating from a common ink chamber through a pressure chamber to a nozzle opening. By deforming the elastic film, a flow passage unit formed by joining a flow path forming substrate having a flow path formed thereon and an elastic film sealing one opening surface of the pressure chamber and the common ink chamber in a laminated state. In an ink jet recording head having an electromechanical transducer for changing the volume of the pressure chamber,
By removing a part of the elastic film facing the common ink chamber halfway in the thickness direction, the thickness of the part corresponding to the common ink chamber is made smaller than the thickness of the part corresponding to the pressure chamber, and the common ink chamber is removed. An ink jet recording head characterized in that the compliance of a portion corresponding to the above is relatively increased.

According to a second aspect of the present invention, the flexural rigidity of the portion of the elastic film corresponding to the common ink chamber is relatively smaller than the flexural rigidity of the portion corresponding to the pressure chamber. Item 2. An ink jet recording head according to item 1.

According to a third aspect of the present invention, there is provided a flow path forming substrate in which a series of ink flow paths communicating with a nozzle opening from a common ink chamber via a pressure chamber and one opening surface of the pressure chamber and the common ink chamber. An ink jet recording head, comprising: a channel unit formed by joining an elastic film to be sealed in a laminated state; and an electromechanical transducer that changes the volume of the pressure chamber by deforming the elastic film. By removing the part corresponding to the common ink chamber in the elastic film to the middle in the thickness direction, the thickness of the part corresponding to the pressure chamber is made thicker than the thickness of the part corresponding to the common ink chamber, and it corresponds to the pressure chamber The ink jet recording head is characterized in that the bending rigidity of the portion is relatively increased.

According to a fourth aspect of the present invention, the elastic film is formed of a two-layer composite film material composed of an adhesive layer and an elastic film layer, and the adhesive layer in a portion corresponding to the common ink chamber is selectively formed. The ink jet recording head according to any one of claims 1 to 3, wherein the ink jet recording head is removed.

According to a fifth aspect of the present invention, in the ink jet recording head according to any one of the first to fourth aspects, the removal of the elastic film is performed by a physical / chemical treatment. is there.

Here, "physical / chemical treatment" refers to treatment using electric energy, chemical energy, electrochemical energy, light energy, heat energy, or the like as an energy source for processing. In short, it means processing using energy other than mechanical energy.

According to a sixth aspect of the present invention, there is provided the ink jet recording head according to the fifth aspect, wherein the physical / chemical processing is a plasma ashing processing.

According to a seventh aspect of the present invention, there is provided the ink jet recording head according to the fifth aspect, wherein the physical / chemical treatment is a dry etching treatment.

According to an eighth aspect of the present invention, there is provided the ink jet recording head according to the fifth aspect, wherein the physical / chemical treatment is a wet etching treatment.

According to a ninth aspect of the present invention, there is provided an ink jet recording head according to any one of the first to eighth aspects, wherein the elastic film is supported by a frame-shaped support plate. .

According to a tenth aspect of the present invention, there is provided an ink jet recording head according to the ninth aspect, wherein the support plate is made of a metal material.

An eleventh aspect of the present invention is characterized in that an island for fixing the displacement surface of the electromechanical transducer is provided on the surface of the elastic film opposite to the pressure chamber. An inkjet recording head according to any one of claims 1 to 10.

According to a twelfth aspect of the present invention, the island portion is
12. The ink jet recording head according to claim 11, wherein a portion corresponding to the pressure chamber of the support plate base material serving as the support plate is formed by removing in a ring shape.

According to a thirteenth aspect of the present invention, there is provided the ink jet recording head according to any one of the first to twelfth aspects, wherein the electromechanical transducer is constituted by a piezoelectric vibrator.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. Here, FIG. 1 is a cross-sectional view of the ink jet recording head 1 of the present invention, and FIG. 2 is a schematic diagram showing a layer configuration of an elastic plate base 2 ′ to be the elastic plate 2.

The illustrated recording head 1 has a vibrator unit 6 in which a plurality of piezoelectric vibrators 3..., A fixed plate 4, a flexible cable 5 and the like are unitized, and a case 7 in which the vibrator unit 6 can be stored. , A flow path unit 8 joined to the end face of the case 7. The case 7 is a block-shaped member made of a synthetic resin in which an accommodation space 10 whose both front and rear ends are open is formed. The vibrator unit 6 is accommodated and fixed in the accommodation space 10. This vibrator unit 6 has a posture in which the comb-shaped tip of the piezoelectric vibrator 3 faces the opening on the tip side of the accommodation space 10, and the fixing plate 4 is adhered and fixed to the wall surface of the accommodation space 10. I have.

The piezoelectric vibrator 3 is a kind of electromechanical transducer and is formed in a vertically elongated comb shape. For example, it is cut into needles having an extremely narrow width of about 50 μm to 100 μm. The piezoelectric vibrator 3 is a laminated piezoelectric vibrator configured by alternately laminating piezoelectric bodies and internal electrodes, and is a longitudinal vibration (d31 effect) type that can expand and contract in a vertical direction perpendicular to the laminating direction. Of the piezoelectric vibrator. Each of the piezoelectric vibrators 3 has a base end portion bonded to the fixed plate 4, and a free end of the piezoelectric vibrator 3 is protruded outward from an edge of the fixed plate 4. Installed in state. Also, each piezoelectric vibrator 3 that functions as a displacement surface ...
Are fixed in contact with the corresponding island portions 11 (described later). The flexible cable 5 is electrically connected to the piezoelectric vibrator 3 on the side of the base end of the vibrator opposite to the fixed plate 4.

In the flow channel unit 8, the nozzle plate 13 is disposed on one side of the flow channel forming substrate 12 with the flow channel forming substrate 12 interposed therebetween, and the elastic plate 2 is on the opposite side to the nozzle plate 13. It is configured by arranging on the other surface side and joining in a laminated state.

The nozzle plate 13 is a thin plate made of stainless steel having a plurality of nozzle openings 14 formed in rows at a pitch corresponding to the dot formation density. In the present embodiment, for example, 96 nozzle openings 14 are opened at a pitch of 180 dpi, and a nozzle row is formed by these nozzle openings 14. Then, a plurality of nozzle rows are formed corresponding to the types of ink that can be ejected.

The flow path forming substrate 12 includes a common ink chamber 16,
Ink supply port 17, pressure chamber 18, and nozzle communication port 19
This is a plate-like member having an ink flow path formed of. More specifically, the flow path forming substrate 12 includes a plurality of nozzle openings 14.
This is a plate-like member in which a plurality of empty portions serving as the pressure chambers 18 are formed in a state of being partitioned by partition walls, and the ink supply ports 17 and the empty portions serving as the common ink chambers 16 are formed.

The pressure chamber 18 is a chamber which is elongated in a direction orthogonal to the direction in which the nozzle openings 14 are arranged (nozzle row direction), and is composed of a flat concave chamber partitioned by a weir portion 20. The weir portion 20 is formed from the outlet of the common ink chamber 16 to the inlet of the nozzle communication port 19. The ink supply port 17 is formed by the weir portion 20 in the form of a narrow portion having a narrow flow path width. I have. The nozzle communication port 19 is a portion that connects the pressure chamber 18 and the nozzle opening 14 and is formed at one end of the pressure chamber 18, that is, at a position farthest from the common ink chamber 16 in the pressure chamber 18. The common ink chamber 16
This chamber is for supplying ink stored in an ink cartridge (not shown) to each of the pressure chambers 18 and communicates with the other end of the corresponding pressure chamber 18 through an ink supply port 17. In addition, an ink introduction port to which the ink supply pipe 21 communicates is opened substantially at the center of the common ink chamber 16 in the longitudinal direction. Then, ink from an ink cartridge (not shown) is introduced into the common ink chamber 16 from the ink inlet through the ink supply pipe 21.

As described above, a series of ink flow paths sequentially passing through the common ink chamber 16, the ink supply port 17, the pressure chamber 18, and the nozzle communication port 19 are formed in the flow path forming substrate 12. That is, a plurality of ink passages corresponding to the nozzle openings 14 are provided to communicate between the common ink chamber 16 and the nozzle openings 14.

The elastic plate 2 is a composite plate having a structure in which an elastic film 31 is laminated on a frame-shaped support plate 30 made of a stainless steel plate. The island portion 11 is formed at a position corresponding to each pressure chamber 18 on the surface of the elastic film opposite to the pressure chamber 18. This island portion 11 is a joining portion for abuttingly fixing the tip portion of the piezoelectric vibrator 3,
Like the pressure chamber 18, the pressure chamber 18 is formed in a block shape that is elongated in a direction orthogonal to the direction in which the nozzle openings 14 are arranged and is slightly smaller than the plane shape of the pressure chamber 18.

In the recording head 1 having the above structure, the piezoelectric vibrator 3 is extended in the vibrator longitudinal direction,
The island portion 11 is pressed toward the nozzle plate 13, and the elastic film 31 deforms around the island portion, so that the pressure chamber 18 contracts. When the piezoelectric vibrator 3 is contracted in the longitudinal direction of the vibrator, the pressure chamber 18 expands due to the elasticity of the elastic film 31. Then, by controlling expansion and contraction of the pressure chamber 18, the ink pressure in the pressure chamber 18 fluctuates and ink droplets are ejected from the nozzle openings 14.

Next, the structure of the elastic plate 2 constituting the main part of the present invention will be described in detail.

The illustrated elastic plate 2 is made of a composite plate made of an elastic film 31 elastically deformed by the ink pressure and the deformation of the piezoelectric vibrator 3 and a frame-shaped support plate 30 for supporting the elastic film 31. Be composed. This is the elastic film 31
Is more easily handled at the time of production than the elastic film alone, and the production efficiency can be improved.

As a material for forming the support plate 30, a metal material is suitably used from the viewpoint of workability and strength. In this embodiment, stainless steel is used. Also,
The elastic film 31 functions as a sealing portion 31 </ b> A for sealing one opening surface of the pressure chamber 18, and the common ink chamber 16.
It also functions as a compliance part 31B for sealing one of the opening surfaces. The elastic film 31 has a two-layer structure including an elastic film layer 32 and an adhesive layer (AD layer) 33, and the adhesive layer 33 adheres to the support plate 30. Therefore, the elastic plate 2 can be said to have a three-layer structure in which the elastic film layer 32 and the support plate 30 are bonded by the adhesive layer 33 interposed therebetween. A resin film such as PPS (polyphenylene sulfide) is preferably used as the elastic film layer 32, and a urethane-based, polyester-based,
And a resin adhesive such as an epoxy resin.
The thickness of each layer of the elastic plate 2 in this embodiment is, for example, 10 to 60 μm (micrometer) for the support plate 30, 1 to 5 μm for the adhesive layer 33, and 3 to 1 μm for the elastic film layer 32.
0 μm.

The elastic plate 2 is manufactured, for example, by the following procedure. First, as shown in FIG. 2, a three-layer structure is formed by bonding an elastic film layer 32 with a bonding layer 33 interposed therebetween on a support plate base material 30 ′ (that is, a stainless steel plate before processing) serving as the support plate 30. Of the elastic plate base material 2 ′. After the elastic plate base 2 ′ is manufactured, processing is performed on a portion functioning as the sealing portion 31A and a portion functioning as the compliance portion 31B.

With respect to the sealing portion 31A corresponding to the pressure chamber 18, the portion of the support plate base material 30 'is removed in an annular shape to remove the island portion 1A.
Form one. Here, a part of the thickness in the thickness direction is removed so that only the support plate base 30 ′ is selectively removed from the support plate base 30 ′ side. Thus, the elastic film 31 around the island portion 11 is composed of the adhesive layer 33 and the elastic film layer 32. In the compliance part 31B corresponding to the common ink chamber 16, the support plate base 30 'and the adhesive layer 33 are selectively removed. That is, the support plate substrate 30
A part of the support plate substrate 30 ′ and the adhesive layer 33 is partially removed in the thickness direction so as to be selectively removed from the ′ side. Thus, the elastic film 31 of the compliance section 31B is composed of only the elastic film layer 32.

In short, in the present embodiment, the elastic plate base material 2 ′ having a laminated structure composed of a plurality of types of materials having different properties.
Then, the elastic plate 2 is manufactured by performing a removal process for each layer. When the removal is performed in units of layers as described above, only the layer to be removed can be easily removed by utilizing the difference in the properties of the materials constituting each layer. For example, when only the support plate base material 30 ′ made of stainless steel is removed, the stainless steel is easily dissolved, and the adhesive layer 33 and the elastic film layer 32 are treated with a resistant chemical, for example, an acid. In addition, only the support plate substrate 30 'can be easily removed. Similarly, when only the adhesive layer 33 is removed and the elastic film layer 32 is left, the adhesive layer 33 is easily dissolved and the elastic film layer 32 is resistant to chemicals, for example, the adhesive forming the adhesive layer 33. By treating with a solvent, only the adhesive layer 33 can be easily removed.

As described above, when the removal is performed utilizing the difference in the properties of the materials constituting each layer, the thickness of the remaining portion can be made uniform. For example, the compliance portion 31B corresponding to the common ink chamber 16 is made uniform by the thickness of the elastic film layer 32.

The selective removal of the support plate base material 30 'and the adhesive layer 33 is preferably performed by a physical / chemical treatment which enables a fine treatment on the order of μm or less. This physical / chemical treatment refers to a treatment using electric energy, chemical energy, electrochemical energy, light energy, heat energy, or the like as an energy source for processing, for example, plasma ashing, dry etching, wet etching, and And laser processing.

In the plasma ashing, argon (A
r), an inert gas such as helium (He) is converted into a plasma by an arc, and the plasma is jetted from a thin nozzle to selectively remove unnecessary portions with a plasma jet of an ultra-high temperature and a high-speed flow. The dry etching is a process of exposing the masked elastic plate base 2 'in an oxidizing atmosphere or an alkaline atmosphere to selectively etch a non-masked portion. The wet etching is, for example, a process in which a masked elastic plate substrate 2 ′ is brought into contact with a strong alkaline liquid such as KOH to selectively etch a non-masked portion. The laser processing is a processing of irradiating a portion to be removed with a laser beam to selectively remove the portion.

In the present embodiment, the support plate substrate 30 'and the adhesive layer 33 are selectively removed by physical or chemical treatment. However, the treatment using mechanical energy as an energy source for processing ( For convenience, this is referred to as mechanical processing.) For example, by applying pressure to the medium and ejecting it from a nozzle, the medium is caused to collide with a workpiece (that is, the elastic plate base material 2 ′) to process the surface (blast processing, water jet processing, or the like), or the like. ,
The support plate substrate 30 ′ and the adhesive layer 33 may be selectively removed by ultrasonic processing in which the abrasive slurry is processed by vibrating the abrasive slurry with ultrasonic waves.

Further, these physical / chemical treatments and mechanical treatments may be performed alone or in combination with some other treatments. For example, the support plate substrate 30
It is also possible to remove the adhesive layer 33 by a chemical treatment after removing the portion 'by a mechanical treatment. Further, in the chemical treatment, a plurality of treatments may be performed by changing a chemical used.

Then, the sealing portion 31A facing the pressure chamber 18
And the compliance section 31 facing the common ink chamber 16
By performing the removal process on B, the support plate base material 30
'Becomes a frame-shaped support plate 30, and the above-mentioned elastic plate 2 is obtained.

In the elastic plate 2 having such a configuration, the thickness of the compliance portion 31B corresponding to the common ink chamber 16 is smaller than the thickness of the sealing portion 31A corresponding to the pressure chamber 18, and
The compliance of the compliance part 31B is relatively higher than the compliance of the sealing part 31A.
With this configuration, the compliance of the common ink chamber 16 can be increased as compared with the related art, and a pressure wave (ink jet) from the pressure chamber 18 can be absorbed even with a smaller volume. Further, from the viewpoint of bending rigidity, the bending rigidity of the compliance part 31B is relatively smaller than the bending rigidity of the sealing part 31A.
1B is easier to bend and deform, and the compliance of the common ink chamber 16 can be higher than before.

On the other hand, the sealing portion 31A corresponding to the pressure chamber 18
With respect to the thickness, the thickness required for discharging the ink droplets can be secured. That is, since the bending rigidity of the sealing portion 31A is larger than the bending rigidity of the compliance portion 31B, the ink in the pressure chamber 18 can be efficiently pressurized or depressurized. Thereby, high responsiveness can be obtained at the time of ink droplet ejection. Further, in the present embodiment, since the island portion 11 made of stainless steel is provided on the surface of the elastic film opposite to the pressure chamber 18, the bending rigidity is also increased by the island portion 11. Therefore, the pressure in the pressure chamber 18 can be increased and reduced more efficiently.

As described above, the present embodiment has a configuration in which the functionality is enhanced by selectively varying the thickness of one elastic film 31 at a necessary position. Thereby, compliance higher than before can be obtained for the compliance section 31B. And the common ink chamber 1
Since the compliance required as 6 is the same as that of the related art, the common ink chamber 16 can be formed small.
As a result, the size of the recording head 1 can be reduced.
On the other hand, regarding the sealing portion 31A, the compliance portion 31
Since a sufficiently higher rigidity than that of B is obtained, high responsiveness can be obtained when ejecting ink droplets.

It should be noted that the present invention is not limited to the above-described embodiment, but is based on the claims.
Various modifications are possible.

For example, in the present embodiment, the elastic plate 2 is manufactured by performing a layer-by-layer removal process on the elastic plate base material 2 ′ having a laminated structure. It may be removed. For example, Compliance Department 3
Regarding 1B, the elastic film layer 32 may be removed partway to make it extremely thin. Further, the elastic film 31
Is not limited to the configuration of a plurality of layers, and may be configured of a single layer.

Further, a bending vibration type piezoelectric vibrator may be used as the electromechanical transducer. This piezoelectric vibrator has a configuration in which a piezoelectric body is sandwiched between an upper electrode and a lower electrode. The piezoelectric body bends in the direction of an electric field according to a potential difference between the upper electrode and the lower electrode, and changes the volume of the pressure chamber 18. Further, the electromechanical transducer is not limited to the piezoelectric vibrator, and may be any element that causes mechanical deformation by applying a drive signal, and may be, for example, a magnetostrictive element.

In this embodiment, the flow path forming substrate 12
Although the flow channel unit 8 in which the nozzle plate 13 and the nozzle plate 13 are formed by different members has been described as an example, the present invention is not limited to this configuration.
2 may be a channel unit integrally formed.

[0050]

According to the present invention as described above, the following effects can be obtained. That is, by removing a portion of the elastic film facing the common ink chamber halfway in the thickness direction, the thickness of the portion corresponding to the common ink chamber is made thinner than the thickness of the portion corresponding to the pressure chamber. Since the compliance of the portion corresponding to the chamber is relatively increased, the required compliance can be obtained even if the common ink chamber is formed small, and the required thickness is secured for the portion corresponding to the pressure chamber. it can. This makes it possible to promote downsizing of the recording head while maintaining good responsiveness of ink droplet ejection.

Further, by removing a portion of the elastic film corresponding to the common ink chamber halfway in the thickness direction, the thickness of the portion corresponding to the pressure chamber is made larger than the thickness of the portion corresponding to the common ink chamber. Since the bending stiffness of the portion corresponding to the pressure chamber is relatively increased, the required stiffness can be ensured for the portion corresponding to the pressure chamber, and the responsiveness of ink droplet ejection can be favorably maintained. On the other hand, the rigidity of the part corresponding to the common ink chamber can be suppressed lower than that of the part corresponding to the pressure chamber, and the compliance can be increased. As a result, necessary compliance can be obtained even if the common ink chamber is formed small. As a result, it is possible to promote downsizing of the recording head while maintaining good responsiveness of ink droplet ejection.

In the case where the elastic film is composed of a two-layer composite film material composed of an adhesive layer and an elastic film layer, and the adhesive layer corresponding to the common ink chamber is selectively removed. Thus, only the adhesive layer can be easily removed by utilizing the difference in properties between the material constituting the adhesive layer and the material constituting the elastic film layer. Thereby, the film thickness of the portion corresponding to the common ink chamber can be easily made uniform.

When the elastic film is removed by physical or chemical treatment, extremely fine treatment is possible.

If an island for fixing the displacement surface of the electromechanical transducer is provided on the surface of the elastic film opposite to the pressure chamber, the bending rigidity of the portion corresponding to the pressure chamber is provided. Is enhanced by this island. Thereby, the response of the ink droplet ejection is further improved.

[Brief description of the drawings]

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

FIG. 2 is a schematic diagram illustrating a layer configuration of an elastic plate base material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 2 Elastic plate 2 'elastic-plate base material 3 Piezoelectric vibrator 4 Fixed plate 5 Flexible cable 6 Vibrator unit 7 Case 8 Flow path unit 10 Storage space 11 Island part 12 Flow path forming substrate 13 Nozzle plate 14 Nozzle opening Reference Signs List 16 Common ink chamber 17 Ink supply port 18 Pressure chamber 19 Nozzle communication port 20 Weir 21 Ink supply pipe 30 Support plate 30 'Support plate base 31 Elastic film 31A Sealing section corresponding to pressure chamber 31B Corresponding to common ink chamber Compliance part 32 elastic film layer 33 adhesive layer

Claims (13)

[Claims] 1. A flow path forming substrate which forms a series of ink flow paths communicating with a nozzle opening from a common ink chamber via a pressure chamber, and an elastic film for sealing one opening surface of the pressure chamber and the common ink chamber. In the ink jet type recording head provided with a flow path unit formed by joining the elastic body films in a laminated state, and an electromechanical transducer that changes the volume of the pressure chamber by deforming the elastic body film, a common ink chamber in the elastic body film is provided. The thickness of the part corresponding to the common ink chamber is made thinner than the thickness of the part corresponding to the pressure chamber by removing the part facing the Ink-jet recording head, characterized by a dramatic increase. 2. The ink jet type of claim 1, wherein a bending rigidity of a portion of the elastic film corresponding to the common ink chamber is relatively smaller than a bending rigidity of a portion corresponding to the pressure chamber. Recording head. 3. A flow path forming substrate formed with a series of ink flow paths communicating with a nozzle opening from a common ink chamber via a pressure chamber, and an elastic film sealing one opening surface of the pressure chamber and the common ink chamber. In the ink jet type recording head provided with a flow path unit formed by joining the elastic body films in a laminated state, and an electromechanical transducer that changes the volume of the pressure chamber by deforming the elastic body film, a common ink chamber in the elastic body film is provided. By removing the part corresponding to the pressure chamber halfway in the thickness direction, the thickness of the part corresponding to the pressure chamber is made thicker than the thickness of the part corresponding to the common ink chamber, and the bending rigidity of the part corresponding to the pressure chamber is relatively reduced. An ink jet recording head characterized by being enlarged in size. 4. The elastic film is composed of a two-layer composite film material composed of an adhesive layer and an elastic film layer, and a portion of the adhesive layer corresponding to a common ink chamber is selectively removed. The ink jet recording head according to any one of claims 1 to 3, wherein: 5. The ink jet recording head according to claim 1, wherein the elastic film is removed by a physical / chemical treatment. 6. The ink jet recording head according to claim 5, wherein the physical / chemical processing is a plasma ashing processing. 7. The ink jet recording head according to claim 5, wherein said physical / chemical treatment is a dry etching treatment. 8. The ink jet recording head according to claim 5, wherein said physical / chemical treatment is a wet etching treatment. 9. The ink jet recording head according to claim 1, wherein said elastic film is supported by a frame-shaped support plate. 10. The ink jet recording head according to claim 9, wherein said support plate is made of a metal material. 11. An island portion for abuttingly fixing a displacement surface of an electromechanical transducer on a surface of the elastic film opposite to the pressure chamber. The inkjet recording head according to any one of the above. 12. The ink jet recording head according to claim 11, wherein the island portion is formed by removing a portion corresponding to the pressure chamber of the support plate base material serving as the support plate in an annular shape. 13. The device according to claim 1, wherein the electromechanical transducer is constituted by a piezoelectric vibrator.
3. The ink jet recording head according to any one of 2.