JPH09141858A - Ink-jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cross strokes and to improve the quality of printing by preventing the propagation of the oscillation generated by the pressurization by an energy generation element to other channels. SOLUTION: In an ink-jet which performs printing and recording by pressurizing cavity chambers 7 arranged in parallel on a cavity plate 1 selectively by a piezoelectric element 2 to discharge ink droplets form corresponding nozzle holes, the cavity plate 12 itself is formed with a damping material. Accordingly, since a partition wall 8 which partitions the cavity chambers 7 is made from a damping material, the propagation of a pressure wave from a pressurized cavity chamber 7 to other cavity chambers 7 is eliminated, preventing cross strokes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head for performing print recording by selectively ejecting ink from a plurality of ink ejection nozzles, and more specifically, to an ink cavity between ink cavities communicating with each ink ejection nozzle. The present invention relates to an inkjet head that reduces crosstalk due to acoustic effects.

[0002]

2. Description of the Related Art Conventionally, as an ink jet head, for example, one described in Japanese Patent Laid-Open No. 6-206310 has a vibration damping member attached to the periphery thereof. As shown in FIG. 3, the inkjet head disclosed in the same publication has a flow path plate (cavity plate) 93 having a nozzle plate 96 at one end and a common liquid chamber (ink manifold) 94 at the other end, and a piezoelectric element plate ( Energy generating element) 92, and the vibration damping member 9
5, 96 are attached. Here, a large number of nozzle holes are formed in the nozzle plate 96, and the flow path plate 93
A cavity chamber is formed in each nozzle of the piezoelectric element plate 92, and a pressure unit that pressurizes the cavity is formed in the piezoelectric element plate 92.

In this ink jet head, the vibration generated when the piezoelectric element plate 92 is driven to eject ink from the nozzle plate 96 is absorbed by the vibration damping members 95 and 96, thereby preventing noise generation during ink ejection. Then, it tried to improve the quietness.

[0004]

However, although the conventional ink jet head achieves noise suppression to some extent, it cannot prevent crosstalk between channels.

That is, in the ink jet head of FIG. 3, when the piezoelectric element plate 92 selectively pressurizes the cavity chamber of the flow path plate 93, a pressure wave is generated in the ink in the cavity chamber of the pressurized channel, and the corresponding nozzle is ejected. In addition to the ink being ejected from the holes, pressure may cause an acoustic effect to propagate pressure to the ink cavities of adjacent channels, resulting in a pressure wave in the ink in the ink cavities. In this case, the ink leaks from the ink discharge nozzles even in the channels that are not pressurized by the piezoelectric element, and the print quality deteriorates. This is crosstalk. In this ink jet head, since the vibration damping members 95 and 96 are present only outside the head, vibration transmitted to the outside is absorbed and noise is prevented, but vibration inside the head cannot be absorbed. Therefore, crosstalk cannot be prevented.

The present invention has been made in order to solve the above problems of the prior art, and absorbs the vibration generated by the pressurization by the energy generating element inside the ink jet head to prevent crosstalk. It is an object of the present invention to provide an inkjet head with improved print quality.

[0007]

In order to achieve the above object, the invention according to claim 1 is such that a plurality of ink ejection nozzles and a plurality of ink cavities communicating with each ink ejection nozzle and filled with ink are arranged in parallel. It has a cavity plate arranged and an energy generating element for pressurizing the ink in each ink cavity, and pressurizes each ink cavity by the energy generating element to eject ink from a corresponding ink ejection nozzle to print a record. The ink jet head for carrying out the above is characterized in that the cavity plate has partition walls for partitioning the ink cavities from each other, and is entirely formed of a vibration absorbing material.

In this ink jet head, when the energy generating element selectively presses the ink cavity of the cavity plate, a pressure wave is generated in the ink in the pressurized ink cavity, and the pressure wave corresponds to the ink. Ink is ejected by propagating to the ejection nozzles, and print recording is performed. Simultaneously with the generation of the pressure wave by the energy generating element, the vibration due to the pressure tries to propagate to the neighboring ink cavity through the partition of the ink cavity due to the acoustic effect, but the entire cavity plate including the partition absorbs the vibration. Since it is made of the above material, vibration is absorbed and crosstalk does not occur in adjacent ink cavities.

The invention according to claim 2 is the ink jet head according to claim 1, wherein the vibration absorbing material is a titanium alloy.

In this ink jet head, since the entire cavity plate including the partition walls is made of vibration absorbing titanium alloy, the vibration due to the pressurization of the energy generating element is absorbed, and the cross talk to the adjacent ink cavities occurs. Does not happen.

The invention according to claim 3 is the ink jet head according to claim 1, wherein the vibration absorbing material is duplex stainless steel.

In this ink jet head, since the entire cavity plate including the partition wall is made of vibration absorbing dual phase stainless steel, the vibration due to the pressurization of the energy generating element is absorbed, and the ink is crossed to the adjacent ink cavities. Talk does not occur.

The invention according to claim 4 is the ink jet head according to claim 1, characterized in that the vibration-absorbing material is a SUS310 stainless steel sintered body.

In this ink jet head, the entire cavity plate including the partition wall is made of vibration absorbing SUS31.
Since it is formed of a 0 stainless steel sintered body, vibration due to pressurization of the energy generating element is absorbed, and crosstalk to adjacent ink cavities does not occur. In addition, SUS
The 310 stainless steel sintered body is most suitably rolled at a reduction rate of 70 to 90% and annealed at a temperature of 790 to 850 ° C.

The invention according to claim 5 is the ink jet head according to any one of claims 1 to 4, wherein the energy generating element is a piezoelectric element.

In this ink jet head, pressure is applied to the ink cavity by applying a voltage to the piezoelectric element, and printing recording is performed by ejecting ink from the corresponding ink ejecting nozzle.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments embodying the present invention will be described in detail below with reference to the drawings. The ink jet head shown in the perspective view of FIG. 1 generally includes a combination of a cavity plate 1 and a piezoelectric element 2,
Nozzle plate 6 having a large number of nozzle holes 5 is attached to the front surface thereof.

This ink jet head will be further described with reference to the sectional view of FIG. 2 (position AA in FIG. 1). A cavity chamber 7 is provided on the side of the piezoelectric element 2 of the cavity plate 1.
Are provided in parallel, and each cavity chamber 7 is partitioned from each other by a partition wall 8. Each cavity chamber 7 has a one-to-one correspondence with each nozzle hole 5 and is adapted to supply ink. The piezoelectric elements 2 are also provided in a one-to-one correspondence with the respective cavity chambers 7, so that the respective cavity chambers 7 can be selectively pressurized.
In addition, between the cavity plate 1 and the piezoelectric element 2,
A flexible diaphragm 3 is sandwiched between each cavity chamber 7
While being kept airtight, the pressure applied by the piezoelectric element 2 can be transmitted to each cavity chamber 7.

In such an ink jet head, the cavity plate 1 including the partition wall 8 is made of a vibration damping material. Materials for damping properties include titanium alloy, stainless steel, chromium-containing steel, cobalt-containing steel,
There are tungsten-containing steel, molybdenum-containing steel, manganese-copper alloy, magnesium alloy, copper-aluminum-nickel alloy, copper-zinc-aluminum alloy, aluminum-zinc alloy, and the like. In these materials, interphase interfacial flow (two or more phases), domain wall movement (ferromagnetic one), dislocation movement (one containing many dislocations), and twin Energy consumption phenomena such as movement of crystal boundaries (twin type) occur, and mechanical energy of vibration is irreversibly converted into thermal energy, and the vibration is absorbed.

Among these materials, the strength required for the cavity plate 1, the corrosion resistance in the state of being in contact with the ink, the non-elution property to the ink, the corrosion resistance to the atmosphere, the processability, the operating temperature range, and the cost, etc. Considering this, titanium alloy, duplex stainless steel, SUS310 stainless steel sintered body and the like are suitable. Of these, as titanium alloy,
Those containing titanium-nickel based intermetallic compound NiTi as a main component are excellent. This alloy forms twins, and vibrations are absorbed by the movement of twin boundaries. In duplex stainless steel, vibration is absorbed by interphase interfacial flow between the ferrite phase (or martensite phase) and the austenite phase.

Although SUS310 stainless steel is austenitic, vibration is absorbed by a few pores contained in the sintered body and a stagnant region in the recrystallization process. This SUS
The 310 stainless steel sintered body is rolled at a reduction rate of 70 to 90% after sintering, and annealed at a temperature of 790 to 850 ° C. shows the best vibration damping property and also has excellent strength. Further, since this material maintains its vibration damping property unless it is heated to the annealing temperature, it can be applied to an inkjet head using a hot melt type ink.

Next, the piezoelectric elements 2 are made of a material having a piezo effect such as PZT, and are provided in a one-to-one correspondence so as to selectively pressurize each cavity chamber 7 through the vibrating plate 3. , Are driven by the application of voltage.

Next, the operation of the ink jet head will be described.

By driving the piezoelectric element 2, each cavity chamber 7
When pressure is selectively applied through the vibrating plate 3, a pressure wave is generated in the ink inside the pressurized cavity chamber 7, the pressure wave propagates to the corresponding nozzle hole 5, and the ink is ejected there. It The ejected ink droplets adhere to the printing paper to form dots, and the array of dots represents characters and symbols.

The phenomenon that occurs when the cavity 7 is pressurized by the piezoelectric element 2 will be further described. As shown in the enlarged circle of FIG. 2, the piezoelectric element 2A among the piezoelectric elements 2
It is assumed that a voltage is applied to. At this time, the piezoelectric element 2A expands in the vertical direction in the figure and the diaphragm 3 bends.
The cavity chamber 7A immediately below is compressed. Due to this compression, the pressure of the ink in the cavity chamber 7A rises, and this pressure rise is transmitted as a wave to the corresponding nozzle hole 5 to eject the ink.

This pressure wave not only propagates in the ink to reach the nozzle hole 5, but also enters the cavity plate 1 from the ink and tries to propagate to the neighboring cavity chamber 7A and the outside of the ink jet head. However, in the ink jet head of the present embodiment, since the cavity plate 1 including the partition wall 8 is formed of the vibration damping material as described above, the pressure wave that has entered the cavity plate 1 is immediately absorbed. It disappears without reaching the vicinity of the cavity chamber 7 or the outside of the inkjet head.

Therefore, like the conventional ink jet head in which the cavity plate is made of a non-vibrating material, the pressure wave generated in the cavity chamber 7A propagates through the partition wall 8 etc. and enters the neighboring cavity chamber 7. There is nothing to do. Therefore, ink does not leak from the nozzle holes 5 due to crosstalk in the channels other than the driven channel, and the print quality is high. Further, since the pressure wave generated in the cavity chamber 7A is not transmitted to the outside of the inkjet head, noise is not generated during driving and the operation is quiet.

As described above in detail, in the ink jet head according to the present embodiment, the entire cavity plate 1 including the partition wall 8 is made of titanium alloy, duplex stainless steel, SUS310 stainless steel sintered body, etc. vibration damping property. Since the pressure wave generated in the ink in the cavity chamber 7 is not transmitted through the partition wall 8 or the like to the neighboring undriven cavity chamber 7 or the outside, crosstalk or noise is generated. As a result, a quiet inkjet head with high print quality is realized.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various improvements and modifications can be made without departing from the gist of the present invention.

[0030]

As described above, according to the first aspect of the invention, the vibration generated by the pressure applied by the energy generating element is absorbed inside the ink jet head, thereby preventing crosstalk and improving the print quality. A designed inkjet head is provided.

In particular, according to the inventions according to claims 2 to 4, since the material of the cavity plate is a titanium alloy, a duplex stainless steel, and a SUS310 stainless steel sintered body, respectively, vibration exceeds the partition wall and causes vibration. There is provided an inkjet head that is absorbed without propagating to an ink cavity and does not cause crosstalk. SU in particular
According to the invention according to claim 4 which uses the S310 stainless steel sintered body, there is provided an ink jet head which is compatible with hot melt ink.

Further, according to the invention of claim 5, since the energy generating element is a piezoelectric element, each ink cavity of the cavity plate formed of a material for preventing crosstalk is selectively pressurized to perform an ejection operation. An inkjet head capable of performing the above is provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main part of the inkjet head of FIG.

FIG. 3 is a diagram showing an example of a conventional inkjet head.

[Explanation of symbols]

 1 Cavity Plate 2 Piezoelectric Element 5 Nozzle Hole 7 Cavity Chamber 8 Partition

Claims (5)

[Claims] 1. A plurality of ink ejection nozzles, a cavity plate in which a plurality of ink cavities communicating with each ink ejection nozzle and filled with ink are arranged in parallel, and energy for pressurizing the ink in each ink cavity is generated. An ink-jet head having an element and pressurizing each of the ink cavities by the energy generating element to eject ink from a corresponding ink ejection nozzle to perform print recording, the cavity plate partitions the ink cavities from each other. An inkjet head characterized in that it has a partition wall and is entirely formed of a vibration absorbing material. 2. The ink jet head according to claim 1, wherein the vibration absorbing material is a titanium alloy. 3. The inkjet head according to claim 1, wherein the vibration-absorbing material is duplex stainless steel. 4. The inkjet head according to claim 1, wherein the vibration absorbing material is a SUS310 stainless steel sintered body. 5. The inkjet head according to any one of claims 1 to 4, wherein the energy generating element is a piezoelectric element.