JP2003112425A - Inkjet recording head and inkjet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording head and an inkjet recorder wherein nozzles are densified without creating an initial malfunction. SOLUTION: The nozzle 21 consists of a tapered section 22 opened to the side of a pressure generating chamber 12 of which the inner diameter is gradually increased toward the opening side, and a nozzle section 23 communicating with the tapered section 22 of which the diameter is the same in the axis direction. An angle θ of an inclined face in a profile passing through the center of the opening of the tapered section 22 is to be in a range of 10 deg.-20 deg.. The diameter of the opening is made to be smaller than a width of the pressure generating chamber 12 by a predetermined value and a part of the opening is not overlapped with a partition wall 11 or a protruding of an adhesive 25, thereby preventing defective bonding and defective ejection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a vibrating plate which constitutes a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets, and a piezoelectric element is provided through the vibrating plate to displace the piezoelectric element. The present invention relates to an ink jet type recording head and an ink jet type recording apparatus for ejecting ink droplets.

[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 over the entire surface of the diaphragm by a film forming technique as disclosed in Japanese Patent Laid-Open No. 5-286131. It has been proposed that the piezoelectric material layer is cut into a shape corresponding to the pressure generating chamber by a lithographic method and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

Further, in such an ink jet recording head, for example, a nozzle plate having a plurality of nozzle openings formed in a substrate made of stainless steel (SUS) or the like is used, and this nozzle plate forms a pressure generating chamber. Each pressure generation chamber and each nozzle opening communicate with each other by being joined to the flow path forming substrate.

In such a nozzle plate, conventionally, there has been a problem that the shape of the nozzle opening is linear and the ink ejection performance such as the ejection amount and ejection speed of the ink droplet is low. It is proposed that the inner diameter is gradually increased to improve the ink ejection characteristics.

[0008]

However, in such a nozzle plate, since the opening diameter on the pressure generating chamber side becomes relatively large, when the nozzle plate and the flow path forming substrate are bonded to each other Positional deviation from the nozzle opening is likely to occur. Therefore, it is necessary to position and bond the nozzle plate and the flow path forming substrate with relatively high accuracy,
There is a problem that the manufacturing process becomes complicated.

In particular, when the nozzle openings are arranged in a relatively high density, the pressure generating chambers are also arranged in a high density, so that the pressure generating chambers and the nozzle openings are likely to be displaced, and the flow path forming substrate and the nozzles There is a possibility that an initial defect such as a discharge defect due to a defective joint with the plate or a nozzle opening communicating with an adjacent pressure generating chamber may occur.

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 in which the nozzle openings have a high density without causing an initial defect.

[0011]

According to a first aspect of the present invention which solves the above-mentioned problems, a nozzle plate having a plurality of nozzle openings formed therein, and the nozzle openings which are bonded to the nozzle plate via an adhesive agent are provided. A flow path forming substrate defined by a plurality of partition walls, and a piezoelectric device provided on one surface side of the flow path forming substrate via a vibration plate to generate a pressure change in the pressure generating chamber. In an ink jet recording head including an element, the nozzle opening is opened to the pressure generating chamber side and the inner diameter gradually increases toward the opening side, and the inner diameter extends in the axial direction in communication with the taper portion. The tapered portion has an angle θ of 10 ° to 20 ° formed by an inclined surface in a vertical cross section passing through the center of the opening, and the diameter of the opening is equal to that of the pressure generating chamber. Than width In an ink jet recording head, wherein a part of the opening is not overlap the protrusion of the partition wall or the adhesive by reducing the predetermined amount.

In the first aspect, even if the nozzle openings are arranged in a relatively high density, the pressure generating chambers and the nozzle openings can be positioned relatively easily, and the flow path forming substrate and the nozzle plate are joined together. It is possible to prevent an initial defect such as a defect or a discharge defect.

According to a second aspect of the present invention, in the first aspect, the opening diameter φ1 of the taper portion and the width W of the pressure generating chamber.
And φ1 <W−C (constant), this constant C is C = (positioning accuracy between the flow path forming substrate and the nozzle plate) + (width W of the pressure generating chamber) Accuracy) + (amount of protrusion of the adhesive that bonds the flow path forming substrate and the nozzle plate),
Further, the opening diameter φ1 of the taper portion is represented by the following formula represented by an angle θ formed by the inclined surface of the taper portion, the opening diameter φ2 of the nozzle portion, the length ls of the nozzle portion, and the thickness t of the nozzle plate. An ink jet recording head characterized by satisfying the relationship of (1).

[0014]

[Equation 2]

In the second aspect, by forming the opening diameter φ1 of the taper portion to a predetermined size, even if the nozzle openings are arranged at a high density, initial defects such as nozzle clogging can be reliably prevented.

A third aspect of the present invention is the ink jet recording head according to the first or second aspect, characterized in that the arrangement density of the pressure generating chambers is 200 dpi or more.

In the third aspect, since the nozzle openings are arranged at a high density, high speed and high quality printing can be realized.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the nozzle plate has a thickness of 60 μm.
The inkjet recording head is characterized by having a thickness of m to 90 μm.

In the fourth aspect, even if the nozzle openings are arranged at a high density, deterioration of ink ejection characteristics and crosstalk do not occur.

A fifth aspect of the present invention is the ink jet recording head according to any one of the first to fourth aspects, characterized in that the nozzle plate is made of stainless steel (SUS).

In the fifth aspect, the nozzle plate in which the nozzle openings are densely arranged can be formed relatively easily.

In a sixth aspect of the present invention, in any one of the first to fifth aspects, the pressure generating chamber is formed by anisotropic etching, and each layer constituting the piezoelectric element is formed by film formation and a lithography method. The inkjet recording head is characterized in that it is formed.

In the sixth aspect, the pressure generating chamber can be formed with high precision and high density relatively easily.

A seventh 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 sixth aspects.

According to the seventh aspect, it is possible to realize an ink jet recording apparatus capable of high speed and high quality printing.

[0026]

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

(First Embodiment) FIG. 1 is an exploded perspective view showing an ink jet recording head according to a first embodiment of the present invention. 2A is a plan view of FIG. 1, and FIG. 2B is a sectional view taken along the line AA ′ of FIG.

As shown in the figure, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is made of silicon dioxide formed by thermal oxidation in advance. 1-2 [μm] elastic film 50
Are formed.

In this flow path forming substrate 10, a pressure generating chamber 1 defined by a plurality of partition walls 11 is formed by anisotropically etching a silicon single crystal substrate from one side thereof.
2 are juxtaposed in the width direction. Further, a communication portion 13 that communicates with a reservoir 31 of a reservoir forming substrate described later via a communication hole 51 is formed on the outer side in the longitudinal direction. The communicating portion 13 is communicated with one end portion of each pressure generating chamber 12 in the longitudinal direction via the ink supply passage 14.

The pressure generating chambers 12 are arranged at a relatively high density of 200 or more per inch, for example, 360 in this embodiment.

Here, the anisotropic etching is performed by utilizing the difference in etching rate of the silicon single crystal substrate. For example, in this embodiment, the silicon single crystal substrate is set to K.
When it is dipped in an alkaline solution such as OH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane
Forms an angle of about 70 degrees with the (111) plane of
A second (111) plane that makes an angle of about 35 degrees with the (0) plane appears, and the etching rate of the (111) plane is about 1/180 of the etching rate of the (110) plane. Is done using. By such anisotropic etching, it is possible to perform precision machining based on the depth machining of the parallelogram shape formed by the two first (111) planes and the two diagonal second (111) planes. The pressure generating chambers 12 can be arranged in high density.

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 side of the flow path forming substrate 10,
A nozzle plate 20 having a nozzle opening 21 that communicates with the pressure generating chamber 12 on the side opposite to the ink supply path 14 is fixed via an adhesive layer 25 made of an adhesive, a heat-welding film, or the like.

The nozzle plate 20 of this embodiment is made of, for example, stainless steel (SUS) and has a nozzle opening 21.
Comprises a taper portion 22 provided on the pressure generating chamber 12 side and having an inner diameter gradually increasing toward the opening side, and a nozzle portion 23 having a substantially constant inner diameter in the axial direction and ejecting ink droplets.

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 21 that ejects the ink droplet are optimal depending on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Be converted. For example, when recording 360 ink droplets per inch as in this embodiment, the nozzle portion 23 of the nozzle opening 21 is set to 20.
It is necessary to form with a diameter of around [μm] with high precision.

As shown in the enlarged view of FIG. 3, the opening diameter φ1 of the tapered portion 22 of the nozzle opening 21 is determined by the pressure generating chamber 1
2 has a diameter smaller by a predetermined amount than the width W of the pressure generating chamber 1
The taper portion 22 and the protruding portion 25a of the partition wall 11 or the adhesive layer 25 into the pressure generating chamber 12 may also be caused by an error in the dimensional accuracy of the nozzle 2 and the nozzle opening 21 or in the positioning accuracy between the flow path forming substrate 10 and the nozzle plate 20. The size does not overlap.

That is, the opening diameter φ1 of the taper portion 22 and the width W of the pressure generating chamber 12 satisfy the relation of φ1 <WC (constant). Here, the constant C is the positioning accuracy of the flow path forming substrate 10 and the nozzle plate 20, the dimensional accuracy of the width W of the pressure generating chamber 12, and the adhesive layer when bonding the flow path forming substrate 10 and the nozzle plate 20. 25 is a value determined in consideration of assembling conditions such as the protrusion amount, and is about 10
It is about μm.

Further, the angle (tilt angle) θ formed by the inclined surface in the cross section of the tapered portion 22 of the nozzle opening 21 is 10 to 10.
It is preferably 20 °, and for example, in the present embodiment, it is about 15 °.

By forming the nozzle openings 21 in such a shape, even if the nozzle openings 21 are arranged at a relatively high density, the pressure generating chambers 12 and the nozzle openings 21 can be relatively easily and elevated at predetermined positions. The flow path forming substrate 10 and the nozzle plate 20 can be satisfactorily bonded by accurately positioning. Therefore, it is possible to prevent the defective joint between the flow path forming substrate 10 and the nozzle plate 20, and to prevent the nozzle opening 21.
Pressure generation chamber 1 where the nozzle openings 21 are adjacent to each other
It is possible to prevent ejection failure due to communication with the second device.

Here, the respective dimensions of the nozzle opening 21 are as follows: the opening diameter φ1 of the tapered portion 22 of the nozzle opening 21, the inclination angle θ of the tapered portion 22, the opening diameter φ2 of the nozzle portion 23,
The relationship between the length Is of the nozzle portion 23 and the thickness t of the nozzle plate 20 is expressed by the following equation (1).

[0041]

[Equation 3]

The opening diameter φ2 and the length l of this nozzle portion 23
s is determined by the characteristics of the head. For example, in the present embodiment, the opening diameter φ2 of the nozzle portion 23 is about 20 μm,
The length ls was about 20 μm.

Further, as described above, in this embodiment,
Since the pressure generating chambers 12 are arranged at a rate of 360 per inch, and the width W of each pressure generating chamber 12 is about 55 μm, the opening diameter φ1 of the tapered portion 22 is φ1 <55-C.
(Constant).

The constant C is a value determined by the assembling conditions. For example, C = (positioning accuracy of the flow path forming substrate and the nozzle plate) + (dimensional accuracy of the width of the pressure generating chamber) + (adhesive The amount of protrusion).

In this embodiment, the positioning accuracy of the flow path forming substrate 10 and the nozzle plate 20 is about ± 5 μm, and the dimensional accuracy of the width of the pressure generating chamber 12 is about ± 1.5 μm. Since the protruding amount of the adhesive when the 10 and the nozzle plate 20 are bonded is about 5 μm on one side, C = 5 + 1.5 + (5 + 5) = 16.5.
Therefore, the opening diameter φ1 of the tapered portion 22 is φ1 <3
It is set to 8.5 μm.

Further, when the nozzle opening 21 satisfies the above conditions, the thickness t of the nozzle plate 20 is calculated from the above equation (1) according to the inclination angle θ of the taper portion 22. That is, the thickness t of the nozzle plate 20 is
When the inclination angle θ of the taper portion 22 is 10 °, it needs to be about 125 μm or less, and when the inclination angle θ of the taper portion 22 is 20 °, it needs to be about 72 μm or less. For example, in the present embodiment, since the inclination angle θ of the tapered portion 22 of the nozzle opening 21 is 15 °, the thickness t of the nozzle plate 20 needs to be about 90 μm or less.

If the thickness t of the nozzle plate 20 is too thin, the nozzle plate 2 will be ejected when ink is ejected.
0 may be deformed to cause crosstalk, so that the thickness t of the nozzle plate 20 is at least 60 μm.
It is preferably m or more.

Further, if the thickness t of the nozzle plate 20 is too thick, the flow path resistance of the nozzle openings 21 will remarkably increase, which may deteriorate the ink ejection characteristics. Is preferably 90 μm or less.

Therefore, in consideration of these points, the thickness of the nozzle plate 20 is preferably about 60 μm to 90 μm. For example, in this embodiment, it is optimal that the thickness of the nozzle plate 20 is approximately 70 μm to 80 μm.

As a result, the nozzle openings can be densified without causing crosstalk and without deteriorating the ink ejection characteristics, and high speed and high quality printing can be realized.

On the elastic film 50 provided on the flow path forming substrate 10, a lower electrode film 60 having a thickness of, for example, about 0.2 [μm] and a thickness of, for example, about 0.5 to The piezoelectric layer 70 having a thickness of 2 [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 300. Here, the piezoelectric element 300
Indicates a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 7 are used.
0 is patterned for each pressure generation chamber 12.
Further, here, a portion which is composed of one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. 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. Further, 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.

Further, the piezoelectric element 300 of the flow path forming substrate 10
A reservoir forming substrate 30 having a reservoir portion 31, which is a common ink chamber of each pressure generating chamber 12, is joined to the side. In this embodiment, the reservoir portion 31 penetrates the reservoir forming substrate 30 in the thickness direction and extends in the width direction of the pressure generating chamber 12, and as described above, flows through the ink communication hole 51. A reservoir 100 that is in communication with the communication portion 13 of the passage forming substrate 10 and serves as a common ink chamber for each pressure generating chamber 12 is configured.

As the reservoir forming substrate 30, it is preferable to use a material having substantially the same thermal expansion coefficient as that of the passage forming substrate 10 such as glass or ceramic material. It was formed using a silicon single crystal substrate of the same material. As a result, it is possible to surely bond the two even if they are bonded at a high temperature using a thermosetting adhesive.

Further, the reservoir forming substrate 30 has
A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is joined. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a thickness of 6 [μ
m] polyphenylene sulfide (PPS) film)
And the one surface of the reservoir portion 31 is sealed by the sealing film 41. The fixing plate 42 is formed of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 [μm]). Since the region of the fixing plate 42 facing the reservoir 100 is the opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed with only the flexible sealing film 41. The flexible portion 32 is deformable by the change of the internal pressure.

An ink inlet 35 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 outside the central portion in the longitudinal direction of the reservoir 100. Further, the reservoir forming substrate 30 is provided with an ink introducing passage 36 that connects the ink introducing port 35 and the side wall of the reservoir 100.

On the other hand, the piezoelectric element 3 of the reservoir forming substrate 30
In a region facing 00, a piezoelectric element holding portion 33 is provided that can seal the space while ensuring a space that does not hinder the movement of the piezoelectric element 300. The piezoelectric element 300 is hermetically sealed in the piezoelectric element holding portion 33, and the piezoelectric element 30 caused by an external environment such as moisture in the atmosphere.
Prevents the destruction of 0.

The ink jet recording head thus constructed takes in ink from the ink introduction port 35 connected to an external ink supply means (not shown), and fills the interior from the reservoir 100 to the nozzle opening 21 with ink. By applying a voltage between the upper electrode film 80 and the lower electrode film 60 according to a recording signal from an external drive circuit (not shown), the elastic film 50, the lower electrode film 60 and the piezoelectric layer 70 are flexibly deformed. The pressure inside the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

(Other Embodiments) Although one embodiment of the present invention has 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 made of stainless steel (SUS) has been described as an example, but the present invention is not limited to this, and the nozzle plate has substantially the same thermal expansion coefficient as the flow path forming substrate 10. You may make it form with the material of. In this case, since the flow path forming substrate 10 and the nozzle plate 20 have substantially the same deformation due to heat, they can be easily joined using a thermosetting adhesive or the like.

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

In the above embodiment, the ink jet recording head having the flexural displacement type piezoelectric element has been described. For example, a vertical structure having a structure in which a piezoelectric material and an electrode forming material are alternately sandwiched and laminated. It can be applied to an ink jet recording head having a vibration mode piezoelectric element. However, in any case, the diaphragm needs to have a tensile stress.

As described above, the present invention can be applied to ink jet type recording heads having various structures as long as it does not violate the gist thereof.

The ink jet recording head of the above-described embodiment 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. Figure 4
It is a schematic diagram showing an example of the ink jet type recording device.

As shown in FIG. 4, in the recording head units 1A and 1B having an ink jet recording head, the cartridges 2A and 2B constituting the ink supply means are detachably provided, and the recording head units 1A and 1B are attached.
The carriage 3 on which B is mounted is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B are, for example,
The black ink composition and the color ink composition are respectively discharged.

Then, 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 follows the carriage shaft 5. Be moved. On the other hand, a platen 8 is provided on the apparatus body 4 along the carriage 3. The platen 8 can be rotated by the driving force of a paper feed motor (not shown) so that the recording sheet S, which is a recording medium such as paper fed by a paper feed roller or the like, is conveyed on the platen 8. Has become.

[0066]

As described above, according to the present invention, the opening diameter of the taper portion is made narrower than the width of the pressure generating chamber to the extent that the adhesive does not flow into the taper portion due to an error in dimensional accuracy or positioning accuracy. Since the angle formed by the inclined surface in the cross section is 10 ° to 20 °, even if the nozzle openings are arranged at a high density, there is an initial defect such as a bonding defect between the flow path forming substrate and the nozzle plate, or a discharge defect. It is possible to relatively easily position and fix the flow path forming substrate and the nozzle plate without generating the above.

[Brief description of drawings]

FIG. 1 is a 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.

FIG. 3 is an enlarged sectional view showing a main part of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a schematic diagram of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

10 Flow path forming substrate 11 partitions 12 Pressure generation chamber 20 nozzle plate 21 nozzle opening 25 Adhesive layer 50 elastic membrane 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 300 Piezoelectric element

Claims (7)

[Claims] 1. A flow path formation in which a plurality of partition walls define a nozzle plate having a plurality of nozzle openings and a pressure generating chamber that is bonded to the nozzle plate with an adhesive and communicates with the nozzle openings. In an ink jet recording head including a substrate and a piezoelectric element that is provided on one surface side of the flow path forming substrate via a vibration plate to generate a pressure change in the pressure generating chamber, the nozzle opening causes the pressure generation to occur. The taper portion includes a taper portion that opens toward the chamber and has an inner diameter that gradually increases toward the opening side, and a nozzle portion that communicates with the taper portion and that has an inner diameter that is substantially the same in the axial direction. The angle θ formed by the inclined surface in the vertical cross section passing through the center is 10 ° to 20 °, and the diameter of the opening is made smaller than the width of the pressure generating chamber by a predetermined amount, so that a part of the opening is separated from the partition wall or the partition wall. An ink jet recording head is characterized in that so as not to overlap the protrusion of the adhesive. 2. The relationship between the opening diameter φ1 of the tapered portion and the width W of the pressure generating chamber according to claim 1, wherein φ1 <W−
While satisfying C (constant), this constant C is C = (positioning accuracy between the flow path forming substrate and the nozzle plate)
+ (Dimensional accuracy of the width W of the pressure generating chamber) + (amount of protrusion of the adhesive that bonds the flow path forming substrate and the nozzle plate), and the opening diameter φ1 of the tapered portion. Satisfies the relationship of the following expression (1) represented by the angle θ formed by the inclined surface of the taper portion, the opening diameter φ2 of the nozzle portion, the length ls of the nozzle portion, and the thickness t of the nozzle plate. Inkjet recording head characterized by [Equation 1] 3. The ink jet recording head according to claim 1, wherein the pressure generating chambers have an arrangement density of 200 dpi or more. 4. The ink jet recording head according to claim 1, wherein the nozzle plate has a thickness of 60 μm to 90 μm. 5. The ink jet recording head according to claim 1, wherein the nozzle plate is made of stainless steel (SUS). 6. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed by anisotropic etching, and each layer constituting the piezoelectric element is formed by film formation and a lithography method. Characteristic ink jet recording head. 7. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.