JP3359648B2 - Inkjet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional ink jet recording head. FIG. 7 is a cross-sectional view of one of a plurality of nozzles in a direction perpendicular to a flow path.

A vibration source 1 (for example, a piezoelectric element) that is deformed by a voltage is mounted on a vibration plate 2 formed of a metal or plastic material. The vibration plate 2 is joined to a substrate 4 on which a flow path 3 is laid, and the substrate 4 is joined to a nozzle plate 6 having a nozzle 5 formed therein.

[0004] An ink discharger a composed of the vibration source 1, the vibration plate 2, the substrate 4, and the nozzle plate 6 joined as described above is surrounded by a case 7 formed of a plastic material at the outer periphery. I have. A drive line 15 (for example, FPC) for inputting electric energy for driving the vibration source 1 is connected to the vibration source 1. The inside of the flow path 3 is filled with ink for forming the ink particles 8.

In such an ink jet recording head, the substrate 4 vibrates unnecessarily when the vibration source 1 is driven and transmitted to the ink in the flow path 3 in order to discharge the ink particles 8 from the nozzles 5. Would. Further, the vibration at this time is transmitted to each part of the ink jet recording head, and the whole ink jet recording head vibrates. This means that the flow path 3 laid on the substrate 4 vibrates. As a result,
Ink droplets 8 having stable characteristics cannot be obtained, for example, the ejection speed or the weight is not uniform.

Further, unnecessary vibration of the entire ink jet recording head has a problem that noise is generated in the surrounding environment.

This phenomenon becomes more remarkable when the number of driven vibration sources 1 is large.

[0008]

SUMMARY OF THE INVENTION According to the present invention, when a vibration source is driven to eject ink particles in an ink jet recording head, unnecessary vibrations occur in the flow path laid on the substrate and the entire ink jet recording head. Prevent that. This makes it possible to discharge ink particles with stable characteristics,
It is another object of the present invention to provide an ink jet recording head with low noise.

[0009]

SUMMARY OF THE INVENTION In order to solve such a problem, an invention according to claim 1 is to laminate a nozzle plate provided with a plurality of nozzles, a substrate provided with a flow path, and a diaphragm. And surrounding the ink ejection body including a piezoelectric element disposed on the surface of the vibration plate corresponding to the flow path, the nozzle plate of the ink ejection body, and the piezoelectric element to be exposed. and plastic casing, said so as to form a space between said piezoelectric element Plasti
Tsu is disposed inside the click case made, to increase the stiffness and mass, and the metal wall for suppressing the propagation of the vibration of the outside of the ink discharge member, in the space to reach the front Symbol metal wall <br /> Filled silicone-based or epoxy-based mold material. According to a second aspect of the present invention, there is provided a piezoelectric plate in which a nozzle plate provided with a plurality of nozzles, a substrate provided with a flow path, and a vibration plate are laminated, and the surface of the vibration plate is disposed corresponding to the flow path. A plastic case having a mold partition wall surrounding the periphery so as to expose the nozzle plate of the ink discharge body and forming a space between the piezoelectric element, and the space. said silicone filled to reach the mold bulkhead or epoxy molding material, said flop
Surround the periphery of the ink ejection body of the plastic case
Wherein a wall surface of the inner surface against the outer surface of the mold partition wall that
And a metal wall for increasing rigidity and mass and suppressing propagation of vibration of the ink ejecting body to the outside.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 1 is a view showing an ink jet recording head according to the present invention, and shows a fixed position of a metal wall 9.

Inside the case 7 is an ink composed of a plurality of vibration sources 1 (for example, piezoelectric elements), a vibration plate 2, a substrate 4 on which a flow path is laid, and a nozzle plate 6 having a plurality of nozzles. Discharge body a is provided.

A metal wall 9 for suppressing unnecessary vibration is fixed to the fixing portion b or the fixing portion c of the case 7 by using an adhesive or a joining means such as press-fitting.

An embodiment will be described below in detail with reference to a sectional view of the ink jet recording head shown in FIG. still,
Since the effect due to the difference between the fixed parts is not confirmed between the fixed parts b and c in FIG. 1, only the embodiment fixed to the fixed part c will be described.

FIG. 2 shows an embodiment of the ink jet recording head according to the present invention. The figure shows a cross-sectional view in a direction perpendicular to the flow channel.

A vibration source 1 that is deformed by a voltage is mounted on a vibration plate 2 formed of a metal or plastic material. The vibration plate 2 is joined to a substrate 4 on which a flow path 3 is laid, and the substrate 4 is joined to a nozzle plate 6 having a nozzle 5 formed therein.

The ink discharger a composed of the vibration source 1, the vibration plate 2, the substrate 4 and the nozzle plate 6 joined as described above has an outer periphery surrounded by a case 7.
A drive line 15 (for example, FPC) for inputting electric energy for driving the vibration source 1 is connected to the vibration source 1. The inside of the flow path 3 is filled with ink for forming the ink particles 8.

A metal wall 9 (for example, damping aluminum, zinc, thin film) is fixed to the case 7 by an adhesive 11 with a space 10 between the vibration source 1 and the vibration plate 2. When the adhesive 11 is not used, it is fixed by press-fitting. The case 7 is made of a plastic material in order to realize a complicated shape relatively inexpensively and to improve the appearance.
A line hole 16 is provided in the metal wall 9, and the drive line 15 is passed therethrough.

Since the case 7 having increased rigidity and mass is fixed to the ink ejection member a, the vibration of the ink ejection member a generated when the ink particles 8 are ejected can be suppressed.

Further, by fixing the metal wall 9 to the case 7, vibration of the case 7 generated when the ink particles 8 are ejected is also suppressed.

Further, fixing the metal wall 9 to the case 7 improves the strength of the case 7 and the durability against external impacts, and at the same time, allows the vibration source 1 which can be said to be the center of the ink jet recording head to be externally mounted. Foreign matter (for example, metal pieces,
Protect from dust and dust). That is, unnecessary vibration to the flow path 3 filled with the ink can be reduced, and the ink particles 8 having stable characteristics such as a uniform ejection speed and weight can be obtained.
Can be obtained.

Further, noise generated by vibration of the case 7 and the like can be suppressed. The noise at this time was about 65 dB (A) when the metal wall 9 was not fixed, but became about 60 dB (A).
ISO-7779).

Next, a case where a molding material (for example, a silicone resin or an epoxy resin) is sealed in the space 10 will be described. Mold material is space 1 from line hole 15
0 is injected. In a state where nothing is sealed in the space 10, the vibration of the vibration source 1 and the unnecessary vibration of the discharge body a are transmitted to the metal wall 9 and the case 7 via the space 10. However, if a relatively soft mold material is sealed in the space 10, the vibration of the vibration source 1 and the vibration plate 2 is attenuated by the mold material and transmitted, so that the vibration does not reach the case 7 and the metal wall 9. . Further, since the gap between the line hole 16 and the drive line 15 is filled, noise leaking to the external environment can be prevented. At this time, the ink particles 8
The discharge speed and weight were the same as before the molding material was sealed, and no change in characteristics was observed.

When a relatively hard mold material is sealed in the space 10, noise to the external environment can be prevented. However, the vibration source 1 is less likely to vibrate than when a relatively soft mold material is sealed in the space 10, and the ejection speed and weight of the ink particles 8 are slightly reduced. However, the voltage for vibrating the vibration source is about 5V. The characteristics before encapsulation of the mold material can be obtained only by increasing.

In any of the molding materials, the rigidity and mass of the ink discharging member a increase because the molding material contacts the ink discharging member a and is integrated with the metal wall 9 through the molding material. In addition, unnecessary vibration of the ink ejection member a does not occur. Also, by using a mold material with a color that is close to transparent, it is possible to check the state when the mold material is enclosed compared to the opaque mold material, and to prevent foreign matter such as air bubbles and dust from entering the inside of the mold material Encapsulation can be performed uniformly, and the effect of the molding material can be more stably obtained.

By enclosing the molding material in the space 10 as described above, unnecessary vibration of the members of the ink jet recording head can be suppressed. And the noise with respect to the external environment is also reduced, and the noise value is reduced to about 48 dB (A).

Further, the molding material acts as a damper against an external impact, improves the durability of the ink jet recording head against the impact, and protects the vibration source 1, which is the center of the ink jet recording head, from the impact.

FIG. 3 shows an ink jet recording head in the case where the metal wall 9 is not provided with the line holes 16. In this case, the drive line 15 is sandwiched inside the adhesive 11 for joining the metal wall 9 and the case 7. When the joining is performed by press-fitting, it is sandwiched between the metal wall 9 and the case 7. Then, in a state where nothing is enclosed in the space 10,
The noise value is about 55 dB (A).

The noise value is reduced by about 5 dB (A) as compared with the case where the molding material is not sealed in the space 10 in the embodiment of FIG. This is because the vibration is suppressed by the metal wall 9. When the mold material is sealed in the space 10, the noise value is about 45 dB
(A). In the embodiment shown in FIG.
The reason why the noise value is reduced by about 3 dB (A) as compared with the case where the metal wall 9 is enclosed is that unnecessary vibration that could not be attenuated by the molding material is suppressed by the metal wall 9. At this time,
The effect of the hardness of the molding material on the characteristics of the ink particles 8 is the same as in the embodiment of FIG.

In the embodiment shown in FIGS. 2 and 3, ink-jet printing is performed by providing irregularities (for example, ribs) on the respective surfaces and fixing them in order to increase the area of the fixing portion between the metal wall 9 and the case 7. The strength of the recording head can be further improved. Thus, unnecessary vibration can be suppressed and noise can be reduced.

Next, another embodiment will be described with reference to FIG. FIG. 4 shows a cross-sectional view in a direction perpendicular to the flow channel, similarly to the above embodiment. FIG. 4 is different from the embodiment in FIG. 2 in that the case 7 is provided with a mold partition wall 12 by processing such as molding or cutting. The difference is that an injection port 13 is provided in the mold partition wall 12.

First, a case where the molding material is not sealed in the space 10 will be described.

The metal wall 9 is fixed to the case 7 and the mold partition 12 with an adhesive 14 without enclosing anything in the space 10. When this fixing method is not used, the mold partition wall 12 is joined with the adhesive 14 and fixed to the case 7 by press-fitting. The drive line 15 is passed through the inlet 13 and the line hole 16.

The bonding of the metal wall 9 indicates that the metal wall 9 is bonded to each of the case 7 and the mold partition wall 12 so that the bonding area is larger than that of the embodiment shown in FIG. In this way, unnecessary vibration of the case 7 is suppressed.

Then, ink particles 8 having more stable characteristics can be obtained. At this time, the noise is also reduced, and about 65 dB
The noise of (A) was about 55 dB (A).

Next, a case where a molding material (for example, silicone resin or epoxy resin) is sealed in the gap 10 will be described. When the molding material is injected from the injection port 13 or the line hole 15, unnecessary vibration of each part of the ink jet recording head is suppressed, and the ink particles 8 having more stable characteristics than when the molding material is not injected can be obtained.
Further, noise is further suppressed, and is reduced to about 43 dB (A). The same result was obtained when the molding material was sealed in the line hole 16. Further, similarly to the embodiment in FIG. 3, the molding material functions as a damper and protects against external impact.

FIG. 5 shows an embodiment in which the metal wall 9 is not provided with the line hole 16 with respect to the ink jet recording head shown in FIG. In this case, the drive line 15 is sandwiched inside the adhesive 14 for joining the metal wall 9 and the case 7. Then, in a state where nothing is enclosed in the space 10, the noise value is about 50 dB (A). The noise value is reduced by about 5 dB (A) as compared with the case where the molding material is not sealed in the space 10 in the embodiment of FIG.
This is because unnecessary vibration transmitted from the injection port 13 and the line hole 16 to the outside is suppressed by the metal wall 9. When the molding material is sealed in the space 10, the noise value is about 40d.
B (A).

The noise value is reduced by about 3 dB (A) as compared with the case where the molding material is sealed in the space 10 in the embodiment of FIG. This is because it was suppressed by the wall 9. Also, by using a mold material with a color that is close to transparent, it is possible to check the state when the mold material is enclosed compared to the opaque mold material, and to prevent foreign matter such as air bubbles and dust from entering the inside of the mold material Encapsulation can be performed uniformly, and the effect of the molding material can be more stably obtained.

In each of the embodiments shown in FIGS. 4 and 5, the ejection speed of the ink particles 8 in a case where a relatively soft mold material is sealed in the space 10 and a case in which a relatively hard mold material is sealed are described. The effect on the weight is the same as in the embodiment shown in FIGS. 2 and 3. In the case of a hard molding material, if the voltage for oscillating the vibration source 1 is increased by about 5 V, the ejection speed and the weight will be increased by enclosing the molding material. The decrease can be corrected and the characteristics before the molding material is sealed can be obtained.

In the embodiment shown in FIGS. 4 and 5, in order to increase the area of the fixing portion between the metal wall 9 and the case 7 and the mold partition 12, irregularities (for example, ribs) are provided on the respective surfaces. By fixing, the strength of the ink jet recording head can be further improved. Thereby, unnecessary vibration can be suppressed and noise can be reduced.

FIG. 6 shows a further improved embodiment according to the present invention. First, a method of joining the case 7 will be described. Vibrating plate 2, substrate 4 on which flow path 3 is laid, and nozzle 5
The case 7 joined to each of the nozzle plates 6 having the holes is provided with a step so as to form a joint d, and the area to be joined is larger than that in the embodiment shown in FIGS. Has become. That is, unnecessary vibration of the ink discharger a is increased by increasing the bonding area with the case 7 so that the vibration can be reduced.
It is shown that the transmission is more efficiently performed by the metal wall 9. At this time, the effect is further improved by increasing the thickness of the case 7.

Next, the shape of the metal wall 9 will be described.

In the embodiment shown in FIGS. 2 and 3, the metal wall 9 has a plate-like shape. On the other hand, in the embodiment of FIG. 6, the vibration source 1 is formed so as to cover the vibration source 1 while avoiding the vibration source 1.
Then, as shown in FIG. 6, the metal wall 9 is fixed to each of the case 7 and the diaphragm 2 using an adhesive 11. When the fixing method is not used, the diaphragm 2 is joined with the adhesive 11 and fixed to the case 7 by press-fitting. The drive line 15 is passed through a line hole 16. When the line hole 16 is not provided in the metal wall 9, the drive line 15 is sandwiched inside the adhesive 11 for joining the metal wall 9 and the case 7, as in the embodiment in FIG. .
When the joining is performed by press-fitting, it is sandwiched between the metal wall 9 and the case 7. When the metal wall 9 is used in this manner, the strength of the entire ink jet recording head is improved, and unnecessary vibration of members constituting each part of the ink jet recording head can be suppressed.

By performing the method shown in FIG. 6, ink particles 8 having more stable characteristics can be obtained. Further, the influence of noise to the outside is reduced.

[0045]

According to the present invention as described above, according to the present invention, i
Unnecessary vibration is applied to the case member of the ink jet recording head.
By providing a metal wall to suppress
Substrate or inkjet generated when ink droplets are ejected
Unnecessary vibrations of the entire recording head can be prevented , and ink droplets can be stably ejected while reducing noise.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a fixing position of a metal wall of an ink jet recording head according to the present invention.

FIG. 2 is an explanatory diagram showing an ink jet recording head according to the present invention.

FIG. 3 is an explanatory diagram showing an ink jet recording head according to the present invention.

FIG. 4 is an explanatory diagram showing an ink jet recording head according to the present invention.

FIG. 5 is an explanatory diagram showing an ink jet recording head according to the present invention.

FIG. 6 is an explanatory diagram showing an ink jet recording head according to the present invention.

FIG. 7 is an explanatory view showing a conventional ink jet recording head.

[Explanation of symbols]

 a Ink ejector b Fixed part c Fixed part d Joint 1 Vibration source 2 Vibrating plate 3 Flow path 4 Substrate 5 Nozzle 6 Nozzle plate 7 Case 8 Ink particles 9 Metal wall 10 Space 11 Adhesive 12 Mold partition 13 Injection 14 Adhesion Agent 15 Drive line 16 Line hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01L 41/09 (72) Inventor Hideaki Suzuki 3-5-5 Yamato, Suwa-shi, Nagano Pref. Seiko Epson Corporation (56) Reference Document JP-A-2-150354 (JP, A) JP-A-3-10844 (JP, A) JP-A-2-307754 (JP, A) JP-A-1-122441 (JP, A) JP-A-1- 87355 (JP, A) JP-A-58-5263 (JP, A) JP-A-59-176549 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/045 B41J 2 / 055 B41J 29/00

Claims (2)

(57) [Claims] 1. A method according to claim 1, further comprising: laminating a nozzle plate having a plurality of nozzles, a substrate having a flow path formed thereon, and a vibration plate, and a piezoelectric element disposed on the surface of the vibration plate corresponding to the flow path. A plastic case surrounding the ink ejection body, the nozzle plate of the ink ejection body, and the piezoelectric element, and the plastic case so as to form a space between the piezoelectric element and the plastic case. A metal wall for increasing rigidity and mass, and suppressing propagation of vibration of the ink ejecting body to the outside,
An ink-jet recording head comprising: a silicone-based or epoxy-based molding material filled in the space so as to reach the metal wall. 2. A method according to claim 1, further comprising: laminating a nozzle plate having a plurality of nozzles formed therein, a substrate having a flow path formed thereon, and a vibration plate, and a piezoelectric element disposed on the surface of the vibration plate corresponding to the flow path. A plastic case having a mold partition wall surrounding the periphery so as to expose the nozzle plate of the ink discharge body, and forming a space between the piezoelectric element, and the mold in the space. and the silicone-based or epoxy-based molding material filled to reach the partition wall, the ink ejection of the plastic casing
A metal wall that is joined to the inner surface of the wall surrounding the outlet and the outer surface of the mold partition wall, increases rigidity and mass, and suppresses propagation of vibration of the ink ejector to the outside; An ink jet recording head comprising: