JP2001179973A - Ink jet recording head - Google Patents

Abstract

(57) [Object] To provide an ink jet recording head having a structure which eliminates the need for a flow path forming plate such as a reservoir forming substrate, is suitable for increasing the number of nozzles, and can reduce the manufacturing cost. SOLUTION: A diaphragm 40 of an actuator unit is provided.
To the cavity forming substrate 30 in which the pressure generating chamber 32 is formed.
Above the pressure generating chamber 32, and the vibration plate 40
An ink supply port 4 communicating with the pressure generation chamber 32 is formed through a region outside the pressure generation chamber 32, and an ink supply section 50 is disposed as a support member on the vibration plate 40 side of the actuator unit. 51 is connected to the ink supply port 4, and the pressure generating chamber 32 is connected to the ink supply tank 50.
The thin portion 52 that absorbs the pressure fluctuation is formed.

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 for ejecting ink droplets from nozzle openings by changing the volume of a pressure generating chamber via a vibrating plate using a piezoelectric vibrator or the like.

[0002]

2. Description of the Related Art A conventional ink jet recording head comprises, for example, an actuator unit 1 and a channel unit 2, as shown in FIG. In the actuator unit 1, a vibration plate 140 is disposed as a first lid member on one side of a cavity forming substrate 130 having a pressure generating chamber 132, and the piezoelectric vibrator 3 is fixed on the surface thereof. A flow path forming substrate 120 is disposed as a second lid member on one side of the substrate, and through holes 121 and 122 as connection flow paths with the flow path unit 2 are formed in the flow path forming substrate 120. The channel unit 2 is configured by sequentially laminating an ink supply port forming substrate 90, a reservoir forming substrate 80, and a nozzle plate 110 in a liquid-tight manner.

Then, a driving signal is applied to the piezoelectric vibrator 3 to cause the vibration plate 140 to be in, for example, the pressure generating chamber (cavity) 13.
When the ink is deformed to the second side, the ink in the pressure generating chamber 132 is pressurized, and a part of the through hole 121 of the flow path forming substrate 120, the through hole 92 of the ink supply port forming substrate 90, and the through hole of the reservoir forming substrate 80. Through the nozzle 82, the ink flows into the nozzle opening 111 and is ejected as an ink droplet. Then, the pressure generating chamber 1
32 is supplied with ink from the reservoir 81 of the reservoir forming substrate 80, through the ink supply port 91 of the ink supply port forming substrate 90, and from the through hole 122 of the flow path forming substrate 120.

[0004] This type of ink jet recording head is
In general, the piezoelectric vibrator 3 is adhered to a partial area of the vibration plate 140 constituting a cover member of the pressure generating chamber 132, and the volume of the pressure generating chamber 132 is changed by bending displacement of the piezoelectric vibrator 3 to form an ink. The pressure generating chamber 13 generates droplets.
2 is capable of displacing a large area, so that ink droplets can be stably generated.

[0005]

However, in the conventional ink jet recording head, the channel unit 2 is laminated on the actuator unit 1, that is, the channel forming plate such as the reservoir forming substrate 80 and the ink supply port forming substrate 90 is formed. Since the basic configuration is to use the components in a stacked configuration, the number of components is large, and structural simplification is desired.

Further, it is desired to increase the number of nozzles in order to improve the image quality and increase the speed. However, in the case of increasing the number of nozzles, variations are likely to occur between recording heads and reservoirs, and the ejection characteristics of ink droplets are reduced. It was difficult to make it uniform.

Accordingly, an object of the present invention is to solve the above-mentioned problems, eliminate the need for the flow path forming plate such as the reservoir forming substrate and the ink supply port forming substrate, is suitable for increasing the number of nozzles, and greatly reduce the manufacturing cost. It is an object of the present invention to provide an ink jet recording head capable of performing the above-described operations.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object. According to the first aspect of the present invention, the volume of a pressure generating chamber is increased by a pressure generating means via a diaphragm. In an ink jet recording head having an actuator unit that ejects ink droplets from nozzle openings by changing the ink supply unit on the diaphragm side of the actuator unit, the diaphragm of the actuator unit is provided with a plurality of pressure generating chambers. On the cavity forming substrate on which is formed, extending outside each pressure generating chamber,
An ink supply port communicating with each pressure generation chamber was formed by penetrating the area outside the plurality of pressure generation chambers of the vibration plate for each pressure generation chamber, and the ink supply port was communicated with the ink supply section. An ink jet recording head characterized in that:

The diaphragm side of the actuator unit is the side opposite to the nozzle plate side across the pressure generating chamber, and is the back side of the pressure generating means provided on the diaphragm.

According to a second aspect of the present invention, there is provided an ink jet recording head according to the first aspect, wherein the ink supply section is formed so as to seal the pressure generating means of the actuator unit.

According to a third aspect of the present invention, there is provided the ink jet recording head according to the first or second aspect, wherein the ink supply section comprises an ink supply tank.

According to a fourth aspect of the present invention, there is provided an ink-jet recording apparatus according to any one of the first to third aspects, wherein a thin-walled portion is formed in the ink supply section to absorb pressure fluctuations in the pressure generating chamber. Head.

According to a fifth aspect of the present invention, the ink outlet of the ink supply section is directly joined to the ink supply port of the vibration plate of the actuator unit, and the vibration plate is provided by the ink supply section as a support member. 5. The ink jet recording head according to claim 1, wherein a partition wall of the pressure generating chamber is fixed via the intermediary of the ink jet recording head.

According to a sixth aspect of the present invention, the ink supply port communicating with the pressure generating chamber has a fine supply port formed in the diaphragm and an ink supply hole formed on the same substrate as the cavity forming substrate. The inkjet recording head according to any one of claims 1 to 5, comprising:

According to a seventh aspect of the present invention, there is provided a cavity forming substrate having a cavity as a pressure generating chamber, a vibration plate arranged as a first lid member on one side of the cavity forming substrate, A flow path forming substrate arranged as a second lid material on the other surface side of the substrate and a nozzle plate arranged on the other surface side of the flow path forming substrate are sequentially liquid-tightly laminated, and the vibration plate A vibrator is fixed as a pressure generating means on a surface corresponding to the pressure generating chamber, and in a region where the vibrator does not exist, an ink supply hole is formed in the cavity forming substrate, and the flow path forming substrate has A communication hole from the ink supply through hole to the pressure generating chamber, and a through hole communicating the pressure generation chamber with the nozzle opening of the nozzle plate are provided, and the vibration plate is provided with an ink supply through hole of the cavity forming substrate. An ink supply type tank, wherein a fine supply port is formed in the diaphragm in the area of the ink supply through-hole, and an outlet of an ink supply tank communicates with the fine supply port. It is a recording head.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a structure near a pressure generating chamber of an actuator unit of a recording head according to the present invention, and FIG.
It is an assembly perspective view shown omitting an adhesive layer.

The actuator unit 1 includes a cavity forming substrate 3 having a cavity as a pressure generating chamber 32.
0, a diaphragm 40 disposed on one side of the cavity forming substrate 30 as a first lid member, and a flow path forming substrate disposed as a second lid member on the other side of the cavity forming substrate 30 20 and the nozzle plate 10 arranged on the other surface side of the flow path forming substrate 20 are sequentially laminated in a liquid-tight manner.

The vibrating plate 40 is made of a thin plate of zirconia having a thickness of about 10 μm, and a piezoelectric vibrator comprising a driving electrode 3a, a piezoelectric body 3b and a common electrode 3c as a pressure generating means on a surface corresponding to the pressure generating chamber 32. (PZT) 3 is fixed.

The cavity forming substrate 30 includes the pressure generating chamber 3
2 is formed of zirconia having a thickness of, for example, about 150 μm and having a plurality of through-holes, and in a region where the piezoelectric vibrator 3 does not exist in the same cavity forming substrate 30 in which the pressure generating chamber 32 is provided. Holes 31 are formed corresponding to the respective pressure generating chambers 32.

The flow path forming substrate 20 has a communication hole 22 from the ink supply hole 31 to the pressure generating chamber 32, and a communication hole connecting the pressure generating chamber 32 to the nozzle opening 11 of the nozzle plate 10. 21 are provided for each of the pressure generating chambers 32. The nozzle plate 10 having the nozzle openings 11 is made of a metal plate such as stainless steel, and is bonded to the flow path forming substrate 20 via an adhesive layer 60.

The vibration plate 40 is provided on the cavity forming substrate 3.
In addition to covering each of the pressure generation chambers 32, the pressure generation chambers 32 extend to both sides in the longitudinal direction of the pressure generation chamber 32 to the same size as the cavity forming substrate 30 in this embodiment.
One of the extending portions of the diaphragm 40 is
A fine supply port 41 is formed to extend from the pressure generating chamber 32 so as to cover the ink supply through-hole 31, and the extension portion of the vibration plate 40 is formed in the area of the ink supply through-hole 31. ing. The fine supply port 41 formed in the diaphragm 40
Forms the ink supply port 4 together with the ink supply holes 31 formed in the cavity forming substrate 30. The fine supply port 41 determines the attenuation characteristic of the pressure generating chamber (specifically, the resistance of the ink supply port 4).
By forming the diaphragm 40 on the diaphragm 40, it is possible to secure the accuracy of forming a predetermined hole diameter and to minimize the variation in the hole diameter.

An ink supply tank (buffer tank) as an ink supply unit also serving as a support member is provided on the vibration plate 40 side of the actuator unit thus formed.
An ink outlet 50 protruding from the bottom surface is directly connected to and communicated with the ink supply port 4 having the fine supply port 41.

That is, conventionally, as shown in FIG. 4, an ink supply port forming substrate 90 is provided and an ink supply port 92 is formed therein. However, in the present invention, the pressure generating chamber 3 of the diaphragm 40 is provided.
This is different from the related art in that an ink supply port 4 that communicates with the pressure generating chambers 32 through the outer region 2 is formed for each of the pressure generating chambers 32.

The leg 53 of the ink supply tank 50 is located on the opposite side of the extending portion of the vibration plate 40 across the pressure generating chamber 32, and the leg 53 is The portion of the vibration plate 40 on the partition wall 34 of the generation chamber 32 is joined. That is, the partition walls 3 on both sides of the pressure generating chamber 32
The portions 3 and 34 are firmly fixed by the outlet 51 of the ink supply tank 50 and the leg 53 of the ink supply tank 50 which are in contact with the portion via the vibration plate 40. The piezoelectric vibrator 3 is connected to an outlet 51 of the ink supply tank 50.
It is provided in the recessed portion 54 between the base and the leg 53 in a sealed state. Therefore, the ink supply tank 50 acts as an insulating sealing cover for the piezoelectric vibrator 3. When the piezoelectric vibrator 3 is sealed by the ink supply tank 50 in this way, it is possible to prevent dew condensation on the piezoelectric vibrator 3 and to prevent foreign matter from entering.

Further, of the extending portion of the diaphragm 40, the flexible cable supporting member 7
0 is in contact therewith and is electrically connected to the drive electrode 3a and the common electrode 3c. As described above, the partition walls 33 and 34 of the pressure generating chamber 32 are supported by the support member (the ink supply tank 5) via the vibration plate 40.
By fixing at 0), the influence of mechanical deformation and vibration of the diaphragm 40 can be improved.

A thin portion 52 is formed in a part of the ink supply tank 50, in this embodiment, a part of the side wall, and the thin portion 52 is deformed outward, so that the pressure generating chamber 32 is formed.
The configuration is such that the pressure rise when the ink flows backward from the nozzle is reduced, and the ink is supplied to the pressure generating chamber 32 quickly by returning to the inside.

That is, in the recording head according to the present embodiment, when the pressure generating chamber 32 is pressurized by the drive signal, a part of the ink in the pressure generating chamber 32 is ejected from the nozzle openings 11 as ink droplets. Ink supply tank 50 serving as an ink supply unit through the ink supply port 4
Backflow to This backflow of ink fluctuates the pressure of the ink supply unit, fluctuates the pressure of the ink in the other pressure generating chambers 32 communicating with the ink supply unit 4 via the ink supply port 4, and changes the ink droplet ejection characteristics. In this embodiment, a thin portion 52 that can be changed by the pressure of the ink is provided on a part of the side wall of the ink supply tank 50 as an ink supply portion. The problem can be solved by absorbing the pressure fluctuation of the ink supply unit. As a result, it is possible to prevent crosstalk due to the pressure fluctuation of the ink supply unit, and to supply the ink to the pressure generation chamber 32 smoothly and promptly by deforming the thin portion 52 inward. in this way,
Since the pressure fluctuation from each pressure generating chamber is absorbed by the thin portion 52, it is particularly suitable for a multi-nozzle type and a long type nozzle.

In the above embodiment, 1 is used as the ink supply unit.
Although the example in which the ink supply tank 50 having the two tank chambers is provided has been described, the form of the ink supply unit is not limited to this. For example, as shown in FIG. Ink chambers 55a, 55b, 5
5c may be divided in the direction in which the pressure generating chambers 32 are arranged, and ink colors may be assigned to the respective sections. Further, another set shown in FIG. 2 or 3 may be juxtaposed to form two rows, one row corresponding to the black ink and one row corresponding to the color ink.

[0029]

As described above, according to the present invention, the following effects can be obtained. That is, since the ink supply section is provided on the back side of the actuator and the ink supply port is formed in the extended portion of the vibration plate, the ink supply path for supplying ink from the ink supply section to the pressure generating chamber is simplified. It is particularly suitable for multi-nozzle and long heads. In addition, the number of components can be reduced as compared with the conventional recording head, thereby facilitating manufacture. Specifically, it is possible to eliminate the necessity of a flow path forming plate such as a reservoir forming substrate or an ink supply port forming substrate, thereby reducing the number of manufacturing steps. When the pressure generating means such as a piezoelectric vibrator is sealed by an ink supply unit such as an ink supply tank, it is possible to prevent dew condensation of the pressure generating means and to prevent foreign matter from entering.

Further, since the thin portion is formed in the ink supply portion, the pressure fluctuation from the pressure generating chamber can be reduced by the deformation of the thin portion. Furthermore, since the partition of the pressure generating chamber is fixed via the diaphragm by the ink supply unit as a support member, mechanical deformation of the diaphragm,
The effect of vibration can be improved. When a fine ink supply port is formed in the vibration plate, variation in the hole diameter can be ultimately reduced. Therefore, the ejection characteristics from each nozzle opening can be uniformed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an ink jet recording head according to the present invention with a structure near a pressure generating chamber of one actuator unit.

FIG. 2 is an assembled perspective view showing an embodiment of the ink jet recording head according to the present invention.

FIG. 3 is an assembled perspective view showing another embodiment of the ink jet recording head of the present invention.

FIG. 4 is a cross-sectional view showing a conventional ink jet recording head having a structure near a pressure generating chamber of one actuator unit.

DESCRIPTION OF SYMBOLS 1 Actuator unit 2 Flow path unit 3 Piezoelectric vibrator 3a Drive electrode 3b Piezoelectric substance 3c Common electrode 4 Ink supply port 10 Nozzle plate 11 Nozzle opening 20 Flow path forming substrate 21 Through hole 22 Communication hole 30 Cavity forming substrate Reference Signs List 31 through-hole for ink supply 32 pressure generating chamber 33, 34 partition wall 40 diaphragm 41 fine supply port 50 ink supply tank 51 outflow port 52 thin part 53 leg part 54 concave part 55 ink chamber 60 adhesive layer 70 flexible cable

Claims (7)

[Claims] 1. An ink jet recording head having an actuator unit for discharging ink droplets from nozzle openings by changing the volume of a pressure generating chamber through a diaphragm by a pressure generating means, wherein the actuator unit is provided on the diaphragm side. An ink supply unit is arranged, and the diaphragm of the actuator unit extends outward from each of the pressure generating chambers on the cavity forming substrate on which the plurality of pressure generating chambers are formed. Ink jet recording, characterized in that an ink supply port communicating with each pressure generating chamber is formed by penetrating an outdoor area portion corresponding to each pressure generating chamber, and the ink supply port is communicated with the ink supply section. head. 2. The ink jet recording head according to claim 1, wherein said ink supply section is formed in a state of sealing the pressure generating means of the actuator unit. 3. The ink jet recording head according to claim 1, wherein said ink supply section comprises an ink supply tank. 4. The ink jet recording head according to claim 1, wherein a thin portion is formed in the ink supply section to absorb pressure fluctuations in the pressure generating chamber. 5. An ink outlet of the ink supply section and the ink supply port of the vibration plate of the actuator unit are directly joined, and the pressure supply chamber is provided by the ink supply section as a support member via the vibration plate. 5. The ink jet recording head according to claim 1, wherein said partition is fixed. 6. An ink supply port communicating with the pressure generating chamber is constituted by a fine supply port formed in a diaphragm and an ink supply through-hole formed on the same substrate as the cavity forming substrate. The ink jet recording head according to any one of claims 1 to 5, wherein 7. A cavity forming substrate having a cavity as a pressure generating chamber, a vibration plate arranged as a first lid member on one side of the cavity forming substrate, and a vibrating plate disposed on another side of the cavity forming substrate. A flow path forming substrate disposed as a second lid member and a nozzle plate disposed on the other surface side of the flow path forming substrate are sequentially laminated in a liquid-tight manner, and correspond to the pressure generating chamber of the diaphragm. A vibrator is fixed on the surface as pressure generating means, and in a region where the vibrator does not exist, an ink supply through-hole is formed in the cavity forming substrate. A communication hole to the pressure generation chamber and a communication hole communicating the pressure generation chamber with the nozzle opening of the nozzle plate are provided, and the vibration plate is extended so as to cover the ink supply hole of the cavity forming substrate. , It said ink fine supply port formed in the region of the supply hole, the ink jet recording head is characterized in that communicates the outlet of the ink supply tank to the fine feed port to the diaphragm.