JPH0957959A - Inkjet device - Google Patents

Abstract

(57) Abstract: A pressure wave generated in an ink chamber communicating with a nozzle that ejects droplets does not affect other ink chambers. SOLUTION: The adhesive 71 is applied only to the side walls 55 provided outside the side walls 5 at both ends of the piezoelectric ceramic plate, and then the manifold member 45 is bonded by aligning the side walls 5 so that corresponding portions 47 correspond to each other. To do. The joint surface between the side wall 5 and the corresponding portion 47 is macroscopically joined, but is microscopically formed with a void. Ink flow path 2
When introduced from 0, due to the surface tension of the ink, the air does not enter the void 30 and an air layer actually exists. The pressure wave generated by the deformation of the side wall 5 reaches the nozzle 50 and ejects an ink droplet. Further, since the pressure wave traveling toward the common ink chamber 46 is absorbed by the air held in the gap 30, it does not propagate to the other ink chambers 4 via the common ink chamber 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet device, and more particularly to a drop-on-demand type multi-nozzle type inkjet device.

[0002]

2. Description of the Related Art In recent years, piezoelectric ink jet heads have been proposed. These heads are provided with a plurality of ink chambers filled with ink, and the volume of the ink chamber is changed by the dimensional displacement of the piezoelectric actuator to generate a pressure wave. The ink is discharged and the ink is introduced into the ink chamber when the volume is increased. Then, by ejecting ink from the ink chamber at a predetermined position, a desired character or image can be formed.

Regarding such an ink jet head, a perspective view of the ink jet head 1 shown in FIG. 2 and FIG.
The operation of the inkjet head 1 shown in FIG. 4 and the sectional view of the inkjet head 1 shown in FIG. 4 will be specifically described.

By joining the piezoelectric ceramic plate 2 having a plurality of side walls 5 and polarized in the direction of the arrow 28 and the lid 6 to each other, a large number of parallels are formed which are spaced from each other in the lateral direction in FIG. The ink chamber 4 is configured. The ink chamber 4 has a rectangular cross section that is long and narrow, and the side wall 5 extends over the entire length of the ink chamber 4. The deformation of the side wall 5 changes the volume of the ink chamber 4 and changes the ink pressure in the ink chamber 4. A drive electrode 7 for applying a drive electric field is formed in a region of the lower half (or upper half) of the surface of the side wall 5, and the surface of the drive electrode 7 serves to insulate the ink from the drive electrode 7. Insulated.

A nozzle plate 60 having a nozzle 50 communicating with one end of each ink chamber 4 is fixed to one end of the piezoelectric ceramic plate 2 and the lid 6 with an adhesive 70. An ink cartridge (not shown) at the other end
The manifold member 40 that supplies ink from the adhesive 7
It is fixed by 1. As shown in FIG. 4, the manifold member 40 is adhered to the side wall 55 and the side wall 5A provided outside the side walls 5 at both ends of the piezoelectric ceramic plate 2,
Adhesive 71 is applied to 5D and adhered. A common ink chamber 41 in which the manifold member 40 is formed communicates with each ink chamber 4.

By doing so, the ink chamber
As shown in FIG. 3, in the inkjet head 1, when the ink chamber 4B is selected according to predetermined print data, the drive electrode 7 is driven by a drive device (not shown).
A driving electric field 1 is provided between each of C, 7D and driving electrodes 7E, 7F.
0 is applied. At this time, since the driving electric field direction and the polarization direction are orthogonal to each other, the side walls 5B and 5C are deformed in a V shape toward the outside of the ink chamber 4B due to the piezoelectric thickness sliding effect.
At this time, ink is supplied into the ink chamber 4B. Then, when the application of the driving electric field 10 is cut off, the side wall 5
B and 5C return to their original positions. Due to this deformation, the ink pressure in the ink chamber 4B becomes a positive pressure, and ink droplets are ejected from the nozzles 50 corresponding to the ink chamber 4B.

[0007]

However, in the conventional ink jet head 1 described above, the pressure wave generated by the volume change in the ink chamber 4B propagates to the common ink chamber 41, and again the ink chamber 4B and other parts. Since the vibration propagates to the nozzle 50 through the ink chambers 4A and 4C and is an extra vibration different from the vibration that becomes the ejection energy of the ink droplet, the problem that the stable ejection of the ink droplet from the nozzle 50 is hindered. was there.

In order to correct this problem, if the distance between the ink chambers 4 is increased so that the extra vibration is less likely to propagate to the other ink chambers 4A and 4C, the head 1 becomes large. Was there.

The present invention has been made in order to solve the above-mentioned problems, and prevents the influence of an extra pressure wave on another ink chamber due to the propagation of the pressure wave generated from the ink chamber, and a stable ink liquid. An object of the present invention is to provide an inkjet device capable of discharging droplets.

[0010]

In order to achieve this object, a plurality of nozzles for ejecting ink and a plurality of ink chambers communicating with the nozzles and filled with ink are provided. In an ink jet device in which a manifold member having a common ink chamber communicating with each ink chamber is joined to an actuator member having a partition wall separating each ink chamber, a portion corresponding to the manifold member corresponding to the partition wall of the actuator member. By providing a gap between the partition wall and the corresponding portion, the pressure wave generated in the ink chamber for ejecting ink droplets is absorbed by the damper effect of the air held in the gap, and Is not propagated to the ink chamber.

In the ink jet apparatus of the second aspect, the volume of the ink chamber changes due to the piezoelectric deformation of the partition wall, at least a part of which is formed of the piezoelectric material, and the pressure wave is generated to eject the ink droplet.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a sectional view showing an ink jet device of the present invention. A plurality of ink chambers 4 are formed by joining the piezoelectric ceramic plate 2 (FIG. 2) having a plurality of side walls 5 and the lid 6 (FIG. 2). At one end of the piezoelectric ceramic plate 2 and the lid 6, a nozzle plate 60 having a nozzle 50 communicating with one end of each ink chamber 4 is provided with an adhesive 70 (FIG. 2).
Has been fixed by. A manifold member 45 that supplies ink from an ink cartridge (not shown) is fixed to the other end by an adhesive 71. The manifold member 45 has a common ink chamber 46 communicating with each ink chamber 4 and a corresponding portion 47 provided at a position corresponding to each side wall 5.

To bond the manifold member 45, the adhesive 71 is applied only to the side walls 55 provided outside the side walls 5 at both ends of the piezoelectric ceramic plate 2, and then the corresponding portion 4 is attached to the side wall 5.
Align and glue so that 7 corresponds. By doing so, the joint surface between the side wall 5 forming the ink chamber 4 and the corresponding portion 47 of the manifold 45 is macroscopically joined, but a microscopic void is formed.
Then, when the ink is introduced from the ink flow path 20, due to the surface tension of the ink, the ink does not enter the void 30 and an air layer actually exists. As described above, the space between the voids 30 is preferably about 500 μm or less, preferably 200 μm, though it depends on the surface tension of the ink used.
m or less is preferable. In this embodiment, the surface tension is 40 mN /
Since the m ink was used, the space between the voids was set to 100 μm or less.

The deformation of the side wall 5 changes the volume of the ink chamber 4, and the pressure wave generated thereby changes to the nozzle 50 to eject ink droplets. Similarly, the generated pressure wave toward the common ink chamber 46 side of the manifold member 45 is held in the void 30 provided at the joint interface between the side wall 5 forming the ink chamber 4 and the corresponding portion 47 of the manifold member 45. Since it is absorbed by the air, it does not propagate to the other ink chambers 4 via the common ink chamber 46.

Even when the ink-jet head of this embodiment produced in this manner was used to eject ink from a large number of nozzles 50 at the same time, the ejection speed of ink droplets did not change. Therefore, high quality recording can be performed.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the present embodiment, the present invention is used in an inkjet device that ejects ink droplets by shear mode deformation of the piezoelectric element, but it may be used in an inkjet device that ejects ink droplets by direct mode deformation of the piezoelectric element. The present invention may be used.

[0018]

As is apparent from the above description, according to the ink jet apparatus of the first aspect, the manifold member is provided with the corresponding portion corresponding to the partition wall of the actuator member, and the partition wall and the corresponding portion are provided. Since there is an air gap between and, the pressure wave generated in the ink chamber for ejecting the ink droplet is absorbed by the damper effect of the air held in the air gap and is not propagated to other ink chambers. For this reason, it is possible to stably eject ink droplets, and it is not necessary to increase the distance between the ink chambers so that it is difficult for the extra vibration to propagate to other ink chambers unlike the conventional ink jet device. Is possible.

According to the ink jet device of claim 2,
At least a part of the partition wall formed of a piezoelectric material undergoes piezoelectric deformation, so that the volume inside the ink chamber changes and pressure waves are generated to eject ink droplets, but the generated pressure waves are retained in the voids. It is absorbed by the damper effect of the generated air and is not propagated to other ink chambers, and stable ink droplet ejection is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an inkjet device of the present invention.

FIG. 2 is a perspective view showing an inkjet device according to the related art and the present invention.

FIG. 3 is an explanatory diagram showing an operation of a conventional ink jet device and the present invention.

FIG. 4 is a cross-sectional view showing a conventional inkjet device.

[Explanation of symbols]

 4 Ink Chamber 5 Side Wall 30 Void 45 Manifold Member 46 Common Ink Chamber 47 Corresponding Section

Claims (2)

[Claims] 1. An actuator member comprising a plurality of nozzles for ejecting ink, a plurality of ink chambers communicating with the nozzles and filled with ink, and a partition wall separating the ink chambers from each other. In an ink jet device in which a manifold member having a common ink chamber communicating with the ink jet device is joined, a corresponding portion is provided in the manifold member corresponding to the partition wall of the actuator member, and a gap is provided between the partition wall and the corresponding portion. Inkjet device characterized by. 2. The inkjet apparatus according to claim 1, wherein at least a part of the partition wall is formed of a piezoelectric material, and the piezoelectric deformation of the partition wall ejects the ink in the ink chamber.