JPH05169652A - Ink jet printer head - Google Patents

Abstract

PURPOSE:To achieve stabilization of ink discharge by attaining densification of a head an improving in a tip position accuracy of a vibrating element by a method wherein the vibrating element is fixed by positioning to a head substrate fixing member with a positioning element and a head substrate. CONSTITUTION:A head substrate 3 is positioned in an enclosed manner to a head substrate guide deformed hole 4e of a head substrate fixing member 4. A vibrating element 1 is positioned with the head substrate fixing member 4 by throwing the head substrate into the head substrate fixing member. Since a positioning jig is not required by the throwing-into structure of the head substrate 3, a manufacturing process becomes easy. Further, since both end surfaces of the head substrate 3 is guide in an enclosed manner with the head substrate fixing member 4 in the throwing into process, a vibrating element 1 consisting of a comparatively brittle laminate piezoelectric element can be prevented from being ruptured owing to collision with other members.

Description

Detailed Description of the Invention

A detailed description of the present invention will be given in accordance with the following items.

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to positioning of a vibrating element.

[0003]

2. Description of the Related Art A conventional vibration element of an ink jet printer head has been positioned and fixed by surrounding each vibrator with a supporting member as disclosed in Japanese Patent Laid-Open No. 58-119871.

[0004]

In the conventional ink jet printer head, each vibrating element is surrounded and supported by a supporting member, and since there is a supporting member between the vibrating elements, the vibrating element interval is narrowed and the head is reduced. There is a problem that it is difficult to increase the density.

Further, since the vibrating element is directly held, the holding length is limited, and since the displacement tip of the vibrating element cannot be held from the point of inhibiting deformation, the vibrating element is held at a position apart from the tip. There is a problem in that it is difficult to position the tip of the vibrating element on the support member with high precision, and stable ink ejection is achieved.

Therefore, a technical object of the present invention is to provide an ink jet printer head of high printing quality, which achieves high density of the head and improves the accuracy of the position of the tip of the vibrating element to stabilize ink ejection. There is something to do.

[0007]

In order to solve the above technical problems, the present invention comprises a vibrating element fixed on a head substrate and the same member as the vibrating element on both sides of the vibrating element. And a positioning element formed in the same processing step, wherein the vibrating element is positioned by the positioning element and the head substrate on the head substrate fixing member, and the head substrate is fixed on the head substrate fixing member. It was

[0008]

According to the above structure of the present invention, the vibrating element is provided on the head substrate and the positioning elements are provided on both sides of the vibrating element, and the positioning element is surrounded and supported by the head substrate fixing member which is a supporting member. Therefore, the vibrating element can be positioned on the head substrate fixing member. Therefore, since it is not necessary to directly surround each vibrating element and hold it by a supporting member, a supporting member that encloses each vibrating element is not required, so that the interval between the vibrating elements can be narrowed and a high-density head can be formed. ..

Further, since the positioning element is made of the same member as the vibrating element, and the positioning element is formed in the same processing step, it is not necessary to join the vibrating element in alignment and to vibrate with the accuracy of the processing machine. Since the positions of the element and the positioning element are determined, the positioning element can be positioned with respect to the vibrating element with high accuracy and can be easily manufactured.

Further, since the vibrating element is positioned on the head substrate fixing member by the positioning element and the head substrate, the positioning element can be positioned on the same plane as the displacement tip of the vibrating element. In other words, the conventional vibrating element supports the vibrating element portion that is as far as possible from the displacement tip from the viewpoint of preventing deformation of the vibrating element, and a slight gap between the supporting member and the vibrating element or a slight inclination of the supporting member prevents the vibrating element from supporting. Although it was difficult to position the tip of the vibrating element with high accuracy because it was enlarged due to the length of the non-restricted portion by the member, according to the present invention, by holding the tip of the positioning element, the displacement tip of the vibrating element is held. The same effect as that of supporting the vibration element can be obtained, and the tip of the vibration element can be positioned on the head substrate fixing member with high accuracy.

Further, by the head substrate and the positioning element,
By positioning the vibrating element on the head substrate fixing member, the vibrating element is restricted by the shape of the vibrating element due to the restriction of the vibrating system.
By fixing the head substrate to the head substrate fixing member using a head substrate that is not restricted, the range of the guide of the head substrate can be widened, and the tip of the vibration element can be positioned on the head substrate fixing member with higher accuracy.

The effect of the positional accuracy of the vibration element on the head substrate fixing member will be described. A member having a pressure chamber and a pressure chamber wall is fixed to the head substrate fixing member.
Since the displacement of the vibrating element is used to displace the pressure chamber wall in the displacement direction, the wall between the pressure chambers has high rigidity, and the wall between the pressure chamber and the tip of the vibrating element is as rigid as the center of the pressure chamber. Is low. Therefore, when the positioning accuracy of the vibrating element is low, the reaction force received by the vibrating element from the pressure chamber wall varies as the density of the head increases, and the pressure applied to the ink in the pressure chamber is not uniformed. For the same reason, if the positioning accuracy is high, the pressure applied to the ink in each pressure chamber is also made uniform, so that the amount of ink ejected from each pressure chamber is made uniform, and an inkjet printer with high printing quality is achieved. A head can be provided.

[0013]

1 (a) is a sectional view showing an embodiment of an ink jet printer head according to the present invention, and FIG. 1 (b) is a partially enlarged view thereof, particularly showing a pressure chamber 5b. The vibrating element 1 is composed of a laminated piezoelectric element. The vibrating element 1 and the positioning element 2 are fixed to the head substrate 3, and the displacement tip 1a of the vibrating element 1 is not restrained by the head substrate 3 and the pressure chamber wall 5a. It is fixed to. In addition, the tip 2 of the positioning element 2
The frontmost surface of a is fixed to the pressure chamber plate 5. When the displacement tip 1a of the vibrating element 1 is fixed to the pressure chamber wall 5a with the above configuration, the tip end 2a of the positioning element 2 contacts the surface of the pressure chamber plate 5 so that the vibrating element 1 is displaced. 1
Since the position of a in the direction of arrow z is determined, the pressure chamber wall 5a is not significantly deformed, and there is an effect that stable manufacturing is possible.

The arrow z indicates the displacement direction of the vibration element 1. The pressure chamber 5b includes a pressure chamber plate 5, a pressure chamber wall 5a, and a nozzle 6a.
Is formed from a nozzle plate 6 having The pressure chamber plate 5 and the nozzle plate 6 have a guide hole 5c and a guide hole 5d and a guide hole 6c and a guide hole 6d for positioning the head substrate fixing member 4, and the guide dowel 4c of the head substrate fixing member 4 is provided. With the guide dowel 4d, the head substrate fixing member 4 is positioned and fixed.

The positioning elements 2 are located on both sides of the vibrating element 1 group, and the tip 2a of the positioning element 2 and the tip 4a of the head substrate fixing member 4 have a slight gap in the arrow y direction, and the positioning element 2 is The head substrate fixing member 4 is positioned. Further, by making the front end 4a of the head substrate fixing member 4 project more than the rear end 4b, the contact with the positioning element 2 can be limited to only the front end, and the front end 1a of the vibrating element 1 composed of a plurality of elements can be closely contacted with the pressure chamber plate 5. They are joined and accurately positioned by the tip 2a of the positioning element 2. The head substrate 3 is fixed to the head substrate fixing member 4 with an adhesive on the overlapping surface of the head substrate fixing member 4 with the hatched portion.

With the above configuration, the displacement tip 1 of the vibrator 1
a is positioned and fixed to the pressure chamber wall 5a in the direction of arrow y through the head substrate 3 → positioning element 2 → head substrate fixing member 4 → pressure chamber plate 5.

Here, the operation will be described. Ink is supplied to the pressure chamber 5b, and when the vibrating element 1 is charged, the vibrating element 1 contracts, and the tip 1a is displaced in the direction away from the nozzle 6a. The volume of the pressure chamber 5b increases with the operation of the vibrating element 1 described above, and ink is further supplied to fill the pressure chamber. Here, when the electric charge stored in the vibrating element 1 is discharged, the vibrating element 1 returns to the initial state and pressurizes the pressure chamber. The pressurized ink escapes to the ink supply side to the pressure chamber and to the nozzle 6a, and the flow velocity of the ink increases due to the effect of the nozzle orifice.
Ink is ejected from a.

FIG. 2 is a plan view for explaining the positioning of the vibration element 1 with respect to the head substrate fixing member 4 in the direction of arrow x, and the pressure chamber plate 5 and the nozzle plate 6 are omitted.

The head substrate 3 is positioned so as to surround the head substrate guide deformed hole 4e of the head substrate fixing member 4, and the vibrating element 1 is moved to the head substrate fixing member 4 by throwing the head substrate into the head substrate fixing member 4. Positioned.

Due to the throwing structure of the head substrate 3,
Since no positioning jig is required, the manufacturing process is facilitated, and since both end surfaces of the head substrate 3 are surrounded and guided by the head substrate fixing member 4 in the throwing process, a relatively fragile laminated piezoelectric element can be obtained. The vibrating element 1 can be prevented from being damaged by a collision with another member.

FIG. 3A is a perspective view of the vibrating element 1, the positioning element 2, and the head substrate 3 when they are assembled.
A thin film electrode 3v and a thin film electrode 3w are formed in a pattern on the surface. The vibrating element 1 and the positioning element 2 are made of laminated piezoelectric elements, and have a thin film electrode 3v as a common electrode.
Through the thin film electrode 3w and the common electrode plate 7 as an electrode,
By charging and discharging the vibrating element 1, the tip 1a of the vibrating element 1 is deformed. (B) is a cross-sectional view of the vibrating element 1 part. In the vibrating element 1, an electrode 1w and a common electrode 1v are formed, and the thin film electrode 3w and the electrode 1w of the head substrate 3 are electrically conductive and further fixed. The common electrode plate 7 and the common electrode 1v are also electrically conductive. Here, from the thin film electrode 3w and the common electrode plate 7 to the vibrating element 1 through the electrode 1w and the common electrode 1v of the vibrating element 1.
When charged to, the tip 1a of the vibration element 1 contracts in the direction of arrow z. Next, when the electric charge charged in the vibrating element 1 is discharged, the contraction of the vibrating element 1 returns to the state before the charging.

FIG. 4 is a process diagram for forming the vibrating element 1 and the positioning element 2. A thin film electrode 3u of 2 μm or less is formed on the surface of the head substrate 3 (state (a)). . A thick film electrode will be described later (c)
A thin film electrode is desirable because electrode peeling easily occurs during processing. Next, the laminated piezoelectric element material 8 composed of the laminated piezoelectric element and the positioning element 2 is bonded to the head substrate 3 and the thin film electrode 3u made of free-cutting ceramics ((b)).
Condition). Next, the thin film electrode 3
The vibrating element 1, the positioning element 2, the thin film electrode 3v, and the thin film electrode 3w are formed by cutting u and the material 8 and processing the head substrate 3 to a depth that allows the head substrate 3 to be slightly cut.
Further, since the vibrating element 1 and the positioning element 2 can be processed in the same process by the slicing machine, by simultaneously machining both outer shapes of the positioning element 2 and the vibrating element 1, the positional accuracy of the positioning element 2 with respect to the vibrating element 1 is It is determined by machine precision, and high precision is achieved (state (c)).

Next, the common electrode plate 7 is electrically connected to the vibrating element 1 (state (d)) so that it becomes equal to that of FIG. 3 (a).

[0024]

According to the above configuration of the present invention, the vibrating element fixed on the head substrate can be fixed by fixing the vibrating element to the head substrate fixing member. Therefore, each vibrating element is surrounded. Since it is not necessary to hold it by a supporting member, and a supporting member that surrounds the vibrating elements is not required, there is an effect that the interval between the vibrating elements can be narrowed and the head density can be increased.

Further, as the positioning element, the vibrating element fixed on the head substrate and the same member as the vibrating element on both sides of the vibrating element are formed in the same processing step, so that the positioning element vibrates. Positioning and joining with the element is not required, and the positions of the vibrating element and the positioning element are determined by the accuracy of the processing machine, so that the positioning element can be positioned with respect to the vibrating element with high accuracy and can be easily manufactured.

Further, since the vibrating element is positioned on the head substrate fixing member by this positioning element and the head substrate, the positioning element can be positioned on the same surface as the displacement tip of the vibrating element. In other words, the conventional vibrating element supports the vibrating element portion that is as far as possible from the displacement tip from the viewpoint of preventing deformation of the vibrating element, and a slight gap between the supporting member and the vibrating element or a slight inclination of the supporting member prevents the vibrating element from supporting. Although it was difficult to position the tip of the vibrating element with high accuracy because it was enlarged due to the length of the non-restricted portion by the member, according to the present invention, by holding the tip of the positioning element, the displacement tip of the vibrating element is held. There is an effect similar to that of supporting the above, and there is an effect that the tip of the vibrating element can be positioned with high accuracy on the head substrate fixing member.

Further, by the head substrate and the positioning element,
By positioning the vibrating element on the head substrate fixing member, the vibrating element is restricted from the shape due to the restriction of the vibration system,
By surrounding and supporting the support member with the support member using the head substrate that is not restricted, there is an effect that the range of the guide can be widened and the tip of the vibrating element can be more accurately positioned on the head substrate fixing member.

Further, since the vibrating element is positioned with high accuracy on the head substrate fixing member, the vibrating element can be positioned with high accuracy on the pressure chamber wall, and the reaction force received from the pressure chamber wall when the vibrating element is displaced. By uniformizing the pressure applied to the ink in each pressure chamber by the vibrating element, the amount of ink ejected from each pressure chamber can be made uniform, and high printing quality can be achieved. ..

[Brief description of drawings]

FIG. 1 is a sectional view of an inkjet printer head of the present invention.

FIG. 2 is a plan view for explaining positioning of the vibrating element 1 of the present invention with the head substrate fixing member 4 in the arrow x direction.

FIG. 3 is a perspective view of a vibrating element 1, a positioning element 2, and a head substrate 3 of the present invention.

FIG. 4 is a process drawing for forming the vibration element 1 and the positioning element 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration element 1a Tip of vibration element 2 Positioning element 3 Head substrate 4 Head substrate fixing member 5 Pressure chamber plate 5a Pressure chamber wall 5b Pressure chamber 6 Nozzle plate 6a Nozzle 7 Common electrode plate 8 Multilayer piezoelectric element material

Claims (1)

[Claims] 1. An ink jet printer which utilizes displacement of a vibrating element to displace a pressure chamber wall in the displacement direction to pressurize ink in the pressure chamber and eject ink droplets from a nozzle communicating with the pressure chamber. In the head, a vibrating element fixed on the head substrate and positioning elements made of the same member as the vibrating element on the both sides of the vibrating element and formed in the same machining step are provided, and the vibrating element is positioned by this positioning element. An inkjet printer head characterized in that the head substrate is fixed to a head substrate fixing member by an element and a head substrate, and the head substrate is fixed to the head substrate fixing member.