JP2003326709A - Liquid granulater, its fabricating method, ink jet recording head, and ink jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid granulater, and its fabricating method, suitable for enhancing the energy efficiency when a specified liquid e.g. ink, is granulated and flown by using a sound collector and for oscillating the sound collector stably. <P>SOLUTION: The liquid granulater comprises the sound collector 10, an oscillating wave supply section 11, a liquid chamber 12, a supporting part 13, a nozzle plate 14, and a nozzle 15. The sound collector 10 is supported, at the joint thereof, by the supporting part 13 and an ultrasonic wave is supplied from the oscillating wave supply section 11 to the sound collector 10. The ultrasonic wave is converged and the energy of the converged ultrasonic wave is utilized for crashing, granulating and flying the ink liquid in the liquid chamber 12. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic ink jet type recording apparatus, and more particularly, to a liquid granulating apparatus suitable for constituting an ink jet type recording head used in an acoustic ink jet type recording apparatus, its manufacturing method, and this liquid. The present invention relates to an inkjet recording head equipped with a granulating device and an inkjet printer equipped with this recording head.

[0002]

2. Description of the Related Art An acoustic ink jet system has been proposed in which ultrasonic waves generated by a vibration generating means such as a piezoelectric element such as a piezo are focused on a point on an ink free surface by a sound collector to eject ink droplets. For example, US Pat.
In No. 08547, ultrasonic waves are focused by a sound collector formed on the vibration generating means, and the ultrasonic waves act on the ink thin film conveyed on the belt brought into contact with the tip of the sound collector to generate ink droplets. It is shown to be ejected.

A similar conventional technique is disclosed in Japanese Patent Laid-Open No.
Japanese Patent No. 168050 discloses a recording device in which a sound collector is provided on the vibration generating means. The vibration generating means is formed of a piezoelectric body and an electrode for applying a voltage to the piezoelectric body, and is arranged in the ink reservoir holding the ink together with the sound collector. The sound collector submerged in the ink is arranged with the tip end formed in a tapered shape facing the ink free surface. Here, when an ultrasonic wave is incident on the bottom of the sound collector from the vibration generating means, its amplitude is amplified as it propagates through the sound collector, and the large-amplitude wave collected by the sound collector is ink. He says that the longitudinal wave generated there pushes up the ink free surface and ejects ink droplets.

[0004]

However, as disclosed in the above-mentioned US Pat. No. 4,308,547, it is difficult to bring the ink thin film into stable contact with the tip of the sound collector, and the contact is unstable. Therefore, the resonance of the sound collector also becomes unstable, which causes variations in the diameter of the ejected ink droplets.

Further, as disclosed in the above-mentioned Japanese Patent Laid-Open No. 4-168050, since the entire sound collector is soaked in the ink, vibration energy propagates from the side surface of the sound collector into the ink. Energy loss increases until the tip of the sound collector is reached. Therefore, the present invention has been made by paying attention to the unsolved problem of such a conventional technique, and uses a sound collector to granulate a predetermined liquid such as ink and cause it to fly. In the apparatus, a liquid granulating apparatus suitable for increasing energy efficiency in liquefying and flying the same and stably vibrating a sound collector, a manufacturing method thereof, and an inkjet equipped with the liquid granulating apparatus A printhead and an inkjet printer are provided.

[0006]

In order to achieve the above object, a liquid granulating apparatus according to a first aspect of the present invention has a half-wavelength of a vibration wave whose length in the propagation direction of the vibration wave is supplied to itself. A sound collector having a predetermined shape designed to be an integral multiple of the length, a vibration wave supply means for supplying a vibration wave to the sound collector, and a liquid chamber for storing a predetermined liquid. A liquid granulating device for focusing the vibration waves by supplying the vibration waves to the sound collector by means, and granulating and flying a part of the liquid in the liquid chamber by the focused vibration waves. A part including the tip of the sound collector is arranged in the liquid chamber, and the other part is arranged in a medium having a lower acoustic impedance than the liquid.

With this structure, a part including the tip of the sound collector whose length in the vibration wave propagation direction is designed to be an integral multiple of the half wavelength of the vibration wave is provided in the liquid chamber. Since the other part is arranged in a medium having a lower acoustic impedance than the liquid in the liquid chamber, for example, the ink liquid made from pure water is put in the liquid chamber and the tip of the sound collector is not included. When the other part is arranged in the air, a part including the tip of the sound collector is arranged in this ink liquid, and the other part is
It is arranged in a medium whose acoustic impedance is lower than that of the liquid in the liquid chamber. For example, when the sound collector is made of silicon, if ultrasonic waves are supplied to the sound collector, the transmittance of energy to the ink liquid in the part of the sound collector that has been exposed to the ink liquid and the air permeability in the other parts. Regarding the transmittance of energy into the inside, since the ink liquid has a higher transmittance, the energy loss (vibration wave energy passing through the ink liquid) in a portion including the tip end portion of the sound collector is larger than in other portions. That is, as compared with the case where the entire sound collector is immersed in the ink liquid, the amount of energy loss in the portion exposed in the air is smaller, and as a result, the energy efficiency is improved. The details of this will be described later.

Generally, in the field of acoustic engineering, the sound collector vibrates so that the amplitude of the tip of the sound collector increases due to resonance, and the length of the sound collector in the vertical cross-sectional direction ( Height) is an integral multiple of the half wavelength of the vibration wave. The amplification factor of the amplitude can be determined by the shape of the sound collector, the cross-sectional area ratio between the root and the tip of the sound collector, and the like. As the shape of the sound collector, there are a shape in which the cross-sectional area changes exponentially, a shape in a cone, and a shape in which the vibration node is discontinuously thin.

According to a second aspect of the liquid granulating apparatus of the present invention, the predetermined shape is designed such that the length in the vibration wave propagation direction is an integral multiple of the half wavelength of the vibration wave supplied to itself. Of the sound collecting body, a vibration wave supplying means for supplying a vibration wave to the sound collecting body, and a liquid chamber for storing a predetermined liquid, and the vibration wave supplying means supplies the vibration wave to the sound collecting body. A liquid granulating device for focusing the vibration wave, and for granulating and flying a part of the liquid in the liquid chamber by the focused vibration wave, including a tip portion of the sound collector. One part is arranged inside the liquid chamber, and the other part is arranged outside the liquid chamber.

With such a configuration, a part including the tip portion of the sound collector whose length in the propagation direction of the vibration wave is designed to be an integral multiple of the half wavelength of the vibration wave is disposed in the liquid chamber. Since the other parts are arranged outside the liquid chamber, for example, if an ink liquid made of pure water is put into the liquid chamber, the other parts that do not include the tip of the sound collector are usually in the air. Therefore, it is arranged in a medium having a lower acoustic impedance than the liquid in the liquid chamber. That is, for example, when an ultrasonic wave is supplied to the sound collector when the sound collector is made of silicon, the transmittance of energy to the ink liquid in the portion of the sound collector that has been exposed to the ink liquid and the other portions. Since the ink liquid has a higher transmittance in the air in the air, the loss of energy in the portion including the tip of the sound collector (vibration wave energy that penetrates the ink liquid) is greater than in other portions. . That is, as compared with the case where the entire sound collector is immersed in the ink liquid, the amount of energy loss in the portion exposed in the air is smaller, and as a result, the energy efficiency is improved. The details of this will be described later.

According to a third aspect of the present invention, in the liquid granulating apparatus according to the first or second aspect, the position of the sound collector at which the displacement of the vibration wave propagating in the sound collector becomes zero. It is characterized in that the portion is supported on the support body side through a support means. That is, the position portion of the sound collector where the displacement of the vibration wave propagating in the sound collector is zero is supported on the support body side through the support means. Therefore,
It becomes possible to vibrate the sound collector more stably than when it is supported at the portion having the displacement.

The invention according to a fourth aspect is characterized in that, in the liquid granulating apparatus according to the third aspect, the inside and outside of the liquid chamber are fractionated by utilizing the supporting means. That is, since the inside and outside of the liquid chamber are fractionated by the support means, for example, by fractionating the liquid chamber so that the liquid does not leak, the device can be used in a predetermined orientation. .

According to a fifth aspect of the present invention, in the liquid granulating apparatus according to any one of the first to fourth aspects, the bottom portion of the sound collector is vibrated from the vibration wave supplying means. In addition to being a wave supply unit, the supply unit is not in contact with the support body side. In other words, the vibration wave supply unit from the vibration wave supply means is provided at the bottom of the sound collector, and the supply unit is brought into a non-contact state so as not to be fixed to the support body side. Since the sound collector can freely vibrate, it is possible to cause the sound collector to vibrate stably and efficiently.

According to a sixth aspect of the present invention, in the liquid granulating apparatus according to any one of the first to fifth aspects, the vibration wave supply means includes a piezoelectric element and a drive signal for the piezoelectric element. And a signal generator for supplying That is, the vibration wave supply means is formed of a piezoelectric element and a voltage supply section that applies a voltage to the piezoelectric element. For example, when the piezoelectric element and the electrode are in close contact with the bottom of the sound collector, In addition, by not fixing the part composed of the piezoelectric element and the electrode to anything other than the sound collector, the sound collector can vibrate more freely than when it is fixed. It is possible to perform stable and efficient vibration.

According to a seventh aspect of the liquid granulating apparatus of the present invention, the predetermined shape is designed such that the length in the vibration wave propagation direction is an integral multiple of the half wavelength of the vibration wave supplied to itself. Of the sound collecting body, a vibration wave supplying means for supplying a vibration wave to the sound collecting body, and a liquid chamber for storing a predetermined liquid, and the vibration wave supplying means supplies the vibration wave to the sound collecting body. A liquid granulation device for focusing the vibration wave by the use of the vibration wave, and for granulating and flying a part of the liquid in the liquid chamber by the focused vibration wave, the vibration wave propagating in the sound collecting body. It is characterized in that the position portion of the sound collector where the displacement of 0 is 0 is supported on the support body side through a support means.

That is, the position portion of the sound collector in which the displacement of the vibration wave propagating in the sound collector is zero is supported on the support body side through the support means. Therefore, it is possible to vibrate more stably than when supporting the portion having the displacement. The invention according to claim 8 is the liquid granulating apparatus according to claim 7, wherein the bottom part of the sound collector is a supply part of the vibration wave from the vibration wave supply means, and the supply part is It is characterized in that it is not in contact with the support side.

That is, a supply portion for the vibration wave from the vibration wave supply means is provided at the bottom of the sound collector, and the supply portion is brought into a non-contact state so as not to be fixed to the support body side. Since it becomes possible for the sound collector to vibrate more freely than in the case described above, it is possible to cause the sound collector to vibrate stably and efficiently. Further, the invention according to claim 9 is characterized in that, in the liquid granulating apparatus according to claim 7 or 8, the inside and outside of the liquid chamber are fractionated by utilizing the supporting means.

That is, since the inside and outside of the liquid chamber are fractionated by the supporting means, the device can be used in a predetermined direction by fractionating the liquid chamber so that the liquid does not leak. It will be possible. The liquid granulating apparatus according to claim 10 of the present invention is a sound collecting device having a predetermined shape designed such that the length in the vibration wave propagation direction is an integral multiple of the half wavelength of the vibration wave supplied to itself. A body, a vibration wave supply unit that supplies a vibration wave to the sound collector, and a liquid chamber that stores a predetermined liquid,
By supplying a vibration wave to the sound collector by the vibration wave supply unit, the vibration wave is focused, and a part of the liquid in the liquid chamber is granulated by the focused vibration wave, and
A liquid granulating device for flying, wherein the bottom part of the sound collector is used as a supply part of the vibration wave from the vibration wave supply means, and the supply part is in a non-contact state with the support side. It has a feature.

That is, a supply portion of the vibration wave from the vibration wave supply means is provided at the bottom of the sound collector, and the supply portion is brought into a non-contact state so as not to be fixed to the support body side. Since it becomes possible for the sound collector to vibrate more freely than in the case described above, it is possible to cause the sound collector to vibrate stably and efficiently. In addition, claim 11
According to a tenth aspect of the present invention, in the liquid granulating apparatus according to the tenth aspect, the vibration wave supply means is composed of a piezoelectric element and a signal generating section that supplies a drive signal to the piezoelectric element.

That is, the vibration wave supply means is formed of a piezoelectric element and a signal generating section for supplying a drive signal to the piezoelectric element. For example, the piezoelectric element and the electrode are closely bonded to the bottom of the sound collector. In this configuration, by not fixing the part consisting of the piezoelectric element and the electrode, the sound collector can vibrate more freely than when it is fixed. And, it becomes possible to perform efficient vibration.

According to the twelfth aspect of the present invention, in the method for manufacturing a liquid granulating apparatus, the length in the vibration wave propagation direction is designed to be an integral multiple of the half wavelength of the vibration wave supplied to itself. A sound collector having a predetermined shape, a vibration wave supply means for supplying a vibration wave to the sound collector, and a liquid chamber for accumulating a predetermined liquid, and the vibration wave supply means vibrates the sound collector. Is a method of manufacturing a liquid granulating device for focusing the vibration wave by supplying the vibration wave, granulating a part of the liquid in the liquid chamber by the focused vibration wave, and flying the liquid. Is disposed in the liquid chamber, and the other portion is disposed in a medium having a lower acoustic impedance than the liquid.

According to a thirteenth aspect of the present invention, in the method for manufacturing a liquid granulating apparatus, the length in the vibration wave propagation direction is designed to be an integral multiple of the half wavelength of the vibration wave supplied to itself. A sound collector having a predetermined shape, a vibration wave supply means for supplying a vibration wave to the sound collector, and a liquid chamber for accumulating a predetermined liquid, and the vibration wave supply means vibrates the sound collector. Is a method of manufacturing a liquid granulating device for focusing the vibration wave by supplying the vibration wave, granulating a part of the liquid in the liquid chamber by the focused vibration wave, and flying the liquid. Is characterized in that a part including the tip portion of the above is disposed inside the liquid chamber, and the other portion is disposed outside the liquid chamber.

According to a fourteenth aspect of the present invention, in the liquid granulating apparatus manufacturing method, the length in the propagation direction of the vibration wave is designed to be an integral multiple of the half wavelength of the vibration wave supplied to itself. A sound collector having a predetermined shape, a vibration wave supply means for supplying a vibration wave to the sound collector, and a liquid chamber for accumulating a predetermined liquid, and the vibration wave supply means vibrates the sound collector. A method for manufacturing a liquid granulating device for focusing the vibration wave by supplying the vibration wave, granulating a part of the liquid in the liquid chamber by the focused vibration wave, and flying the liquid. It is characterized in that the position portion of the sound collector in which any one of the vibration waves having an integral multiple wavelength that propagates is zero is supported by a predetermined supporting means.

According to a fifteenth aspect of the present invention, in the method for manufacturing a liquid granulating apparatus, the length in the vibration wave propagation direction is designed to be an integral multiple of the half wavelength of the vibration wave supplied to itself. A sound collector having a predetermined shape, a vibration wave supply means for supplying a vibration wave to the sound collector, and a liquid chamber for accumulating a predetermined liquid, and the vibration wave supply means vibrates the sound collector. Is a method of manufacturing a liquid granulating device for focusing the vibration wave by supplying the vibration wave, granulating a part of the liquid in the liquid chamber by the focused vibration wave, and flying the liquid. The bottom part of is the supply part of the vibration wave from the vibration wave supply means, and the supply part is in a non-contact state with the support body side.

An ink jet recording head according to a sixteenth aspect of the present invention is characterized by including the liquid granulating apparatus according to any one of the first to eleventh aspects. That is, for example, the liquid granulating device according to any one of claims 1 to 11 is arranged corresponding to each of the nozzle rows in which a plurality of nozzle openings are formed at a constant nozzle pitch, Inks of various types such as black ink and magenta ink are injected into the liquid chambers of these devices, and these inks are granulated and ejected from the nozzle openings to form an image or the like on an object such as paper. An inkjet recording head for recording is configured.

An ink jet printer according to a seventeenth aspect of the present invention is characterized by including the ink jet recording head according to the sixteenth aspect. That is, it is an inkjet printer including the inkjet recording head according to claim 16.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of a liquid granulating apparatus according to the present invention. First, the basic configuration of the liquid granulating apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a first configuration example of a liquid granulating apparatus according to the present invention.

The first structural example 1 of the liquid granulating apparatus is a sound collector 10, a vibration wave supplying section 11, a liquid chamber 12, and a supporting section 1.
3, the nozzle plate 14, and the nozzle 15 are included. In the present embodiment, the sound collector 10 is made of a silicon member, and as shown in FIG. 1, has a shape in which the vibration of the sound collector, which will be described later, is discontinuously thinned from a node to a tip. is doing. A sound collector upper part 10a including the tip end is disposed inside the liquid chamber 12 with this node as a boundary, and a sound collector lower part 10b which is a lower part with the node as a boundary is disposed in the air. Has been done. Further, in the present embodiment, the shape of the tip of the sound collector 10 is flat.

Here, the sound collecting body 10 having a step like this
As shown in FIG. 4, assuming that the vibration velocity and the cross-sectional area of the root and the tip are respectively V ₁ , V ₂ and S ₁ , S ₂ , the vibration velocity expansion rate V ₂ / V ₁ at both end surfaces is Has a relationship such as S ₁ / S ₂ , and an appropriate value can be determined from this relationship. As the simplest shape, an example in which two uniform round bars of 1/4 wavelength (1 / 4λ) are connected will be described.
It has been confirmed by an experiment that a driving frequency of a dozen MHz is necessary to eject a few microliters of microdroplets. If the material of the sound collector is silicon, the speed of sound in silicon is v =
From 8340 [m / s], if the drive frequency is f = 15 [MHz], the total length L of the sound collector is L = 1 / 4λ + 1 / 4λ =
(8340/15/4) × 2 = 281 [μm].

In this embodiment, the step shape is assumed to be dry etching of the silicon substrate, and other shapes can be realized if the material of the sound collector 10 is different. In addition, the knot portion, as shown in FIG.
It is a portion where the displacement of the amplitude of the ultrasonic wave propagating in 0 becomes just 0, and in the present embodiment, it is designed so that the boundary that becomes thinner discontinuously becomes the node portion, and as described above. The sound collector 10 has a structure in which an upper part 10a of the sound collector and a lower part 10b of the sound collector are separated from each other with this node as a boundary.

The vibration wave supply unit 11 includes a piezoelectric element 11a,
The piezoelectric element 11a is configured to include an electrode for applying a drive voltage, a signal generator, and a signal generator 11b including an amplifier. That is, when an alternating voltage is applied to the piezoelectric element 11a, the piezoelectric element 11a is alternately displaced in the direction according to the polarity of the voltage and vibration is generated. This vibration is incident as an ultrasonic wave from the contact portion with the sound collector 10. Here, as the piezoelectric element, an element with stable vibration such as PZT (lead zirconate titanate) can be considered. The piezoelectric element 11a including this electrode is arranged at the bottom of the sound collector 10, and the bottom of the piezoelectric element 11a including further electrodes corresponds to the first configuration example 1 of the liquid granulating apparatus shown in FIG. It is fixed to the constituent base. Here, the bottom portion of the piezoelectric element 11a and the base portion are fixed to each other while avoiding a portion corresponding to the bottom portion of the sound collector 10 and the opposite side of the fixing portion of the piezoelectric element 11a. In FIG. 1, a part of the base part is hollowed out and the bottom part of the piezoelectric element 11a is fixed to the base part, so that it is possible to reduce the interference of the vibration of the piezoelectric element 11a.

In the present embodiment, the liquid chamber 12 stores the ink liquid 17 made of pure water, and the sound collector upper portion 10a is arranged in the liquid chamber 12 as described above. There is. Therefore, the upper part 10 a of the sound collector comes into contact with the ink liquid in the liquid chamber 12. The support 13 is the sound collector 1.
It supports 0 so that it is arranged at an appropriate position, and also plays a role of separating the liquid chamber 12 and air. In the present embodiment, the support portion 13
Supports the position of a node in the sound collector 10.

The nozzle plate 14 is used when the first constitutional example 1 of a plurality of liquid granulating devices is formed into an array and used.
It is intended to eliminate the interference of liquid surface vibration between adjacent liquid surfaces, and to prevent liquid leakage when the same configuration example 1 is used so that the tip of the sound collector 10 faces downward. is there. The nozzle 15 is a hole formed in the nozzle plate 14 in the present embodiment, and ejects ink droplets 18 shown in FIG. 1 in which a part of the ink liquid 17 is granulated to fly toward an object. It is a hole. Here, the nozzle portion may be formed by forming the nozzle plate 14 into another shape having a portion that plays a role of a nozzle, such as a slit shape.

The more specific operation of the liquid granulating apparatus 1 will be described below. As shown in FIG. 1, when an AC voltage having a cycle matched to the shape of the sound collector 10 is applied from the signal generator 11b to the piezoelectric element 11a, the piezoelectric element 10a is displaced with respect to the voltage according to this cycle. Generates vibration. This vibration becomes an ultrasonic wave and is incident on the sound collector 10 from the bottom thereof. Then, the ultrasonic waves propagating inside the sound collector 10 are repeatedly reflected between the tip and the bottom of the sound collector 10, and resonance is caused by these reflected waves and the incident wave from the piezoelectric element 11a. The resonated ultrasonic waves are focused on the upper part 10a of the sound collector due to the tapered shape of the sound collector 10, and the amplitude becomes larger as it goes to the tip end, assisting the resonance due to reflection. The ultrasonic energy transmitted through the ink liquid 17 out of the amplified and focused ultrasonic energy hits the ink liquid 17, whereby a part of the ink liquid 17 becomes a granular ink droplet 18 and the nozzle 15
Will fly from. At this time, as shown in FIG. 1, the sound collector upper part 10a is arranged in the liquid chamber 12, and the sound collector lower part 10b is arranged in the air. In the lower portion 10b, the amount of energy transmitted from the inside of the sound collector 10 to the outside differs between the two. That is, in the present embodiment, the ink liquid 1
Since 7 is made of pure water, the ultrasonic energy that penetrates into the ink liquid 17 at the upper part of the sound collector 10a and the ultrasonic energy that penetrates into the air at the lower part of the sound collector 10b are ink liquids with high density. The ultrasonic energy transmitted through 17 becomes larger.

The principle of transmission of ultrasonic energy will be described below. The ultrasonic energy is divided into a reflection component and a transmission component at the boundary between the sound collector 10 and the ink liquid 17.
Therefore, in order to efficiently fly the ink droplets 18, it is important to reduce the transmission component of ultrasonic energy from the side surface of the sound collector 10 to the surroundings before the ultrasonic waves reach the tip of the sound collector 10. .

Here, the transmittance of ultrasonic energy that is perpendicularly incident on the boundary surface between two media that are in contact with each other on a plane will be described. Ultrasonic waves in the medium of density ρ [kg / m ³ ]
/ s], the product of the density ρ and the speed of sound c is called the acoustic impedance Z [N · s / m ³ ] of the medium, which is the energy of the ultrasonic wave incident perpendicularly to the interface between the two media. Transmittance T
Is expressed by _{T = 1- (Z 1 -Z 2} ) 2 / (Z 1 + Z 2) 2. However, Z ₁ and Z ₂ are acoustic impedances of the respective media. Here, a case where silicon is used for the sound collector 10 and pure water is used for the ink liquid will be described. The density of silicon and the propagation velocity of ultrasonic waves in silicon are 2.33 ×, respectively.
It is 10 ³ [kg / m ³ ] and 8430 [m / s], and the acoustic impedance is Z _s = 19.6 × 10 ⁶ [N · s / m ³ ].
On the other hand, the density of pure water and the propagation velocity of ultrasonic waves in pure water are 1.0 × 10 ³ [kg / m ³ ] and 1500 [m / s], respectively, and the acoustic impedance is Z _w = 1.5. × 10 ⁶ [N · s /
m ³ ]. From this, the transmittance of ultrasonic energy from the sound collector 10 into pure water is calculated to be 26%.

Further, the case where the surrounding of the sound collector 10 is air will be described. The density of air and the propagation velocity of ultrasonic waves in air are 1.29 [kg / m ³ ] and 340 [m / s], respectively, and the acoustic impedance Z _a = 0.44 × 10 ³ [N · s /
m ³ ], from which the transmittance of ultrasonic energy from the sound collector 10 into the air is calculated to be 9 × 10 ⁻³ [%], and the energy transmission is almost zero.

Therefore, the sound collector 10 according to the present embodiment.
Is arranged in the liquid chamber 12 so that the upper part 10a of the sound collector is submerged in the ink liquid 17, and the lower part 10b of the sound collector is disposed.
Is placed in the air, the lower part of the sound collector 10 in the air
The transmission of ultrasonic energy from the sound collector to the air in b is almost zero. In addition, the first of the liquid granulating device
FIG. 2 shows an example in which a recording head 2 for an inkjet printer is configured as an actual application example using a plurality of the configuration example 1 of FIG. In FIG. 2, the sound collector 10 and the piezoelectric element 11a are separated so that the internal structure can be overlooked, but originally, these are closely joined. As shown in FIG. 2, by configuring the recording head 2 for inkjet by a plurality of the present configuration example 1, the ink liquid 17 in each liquid chamber 12 is granulated by the ultrasonic energy focused by the sound collector 10. Printing is performed by causing the ink droplets 18 to fly and adhere to the printer paper. Therefore, the inkjet printer
The head scanning mechanism is provided for moving the recording head 2 in the main scanning direction.

As described above, the first structural example 1 of the liquid granulating apparatus
Since the sound collector upper part 10a of the sound collector 10 is arranged in the liquid chamber 12 and the sound collector lower part 10b is arranged in the space surrounded by the base portion and the support portion 13, When ultrasonic waves are incident on the body 10, the upper part of the sound collector 10a is lower than the lower part of the sound collector 1
The amount by which the ultrasonic energy in the inside penetrates to the outside is larger than 0b, and compared to the case where the entire sound collector 10 is disposed in the liquid chamber 12, the side surface of the sound collector 10 that acts on the granularity. The energy transmitted from a place unrelated to is almost eliminated in the portion arranged in the air, so that the energy loss can be prevented.

Further, since the sound collector 10 has the stepped shape as described above, the ultrasonic energy becomes strong only near the tip. Therefore, depending on the usage, the nozzle plate becomes unnecessary, and further, it is not necessary to form a nozzle having a small diameter. In addition, the sound collector 10 is supported by the support 13 at the position of the node.
Since it is supported by, it is possible to reduce the hindrance to the vibration of the sound collector 10 as compared with the case where it is supported by other than the node portion.

A second structural example of the liquid granulating apparatus according to the present invention will be described with reference to FIG. FIG. 3 is a diagram showing a second configuration example of the liquid granulating device. Here, the same components as those in the first configuration example 1 of the liquid granulating device shown in FIG. 1 are denoted by the same reference numerals and detailed description thereof will be omitted. A second configuration example 3 of the liquid granulating device is a sound collector 10.
A vibration wave supply unit 11, a liquid chamber 12, a support unit 13,
The nozzle plate 14 and the nozzle 15 are included.

The difference from the first configuration example 1 of the liquid granulating device is that the whole of the sound collector 10 is installed in the opposite direction so that the tip end thereof faces downward, and further, it is shown in FIG. like,
The piezoelectric element 11a (including the electrodes) in the vibration wave supply unit 11 is not fixed to any part other than the sound collector 10 on the base portion of the second configuration example 3 of the liquid granulating device. In this way, the piezoelectric element 11a is not fixed,
By supporting only the node of the sound collector 10 by 3, the vibration of the sound collector 10 is not hindered, and it is possible to suppress unnecessary energy consumption.

Here, the oscillatory wave supply unit 11 shown in FIGS. 1 to 3 is defined by claim 1, 2, 5, 6, 7, 8 and claim 1.
0 to claim 15 corresponding to the vibration wave supply means, the support portion 13 corresponds to the predetermined support means according to claim 3, 4, 7, 9, 14 recording for the inkjet printer shown in FIG. The head 2 corresponds to the ink jet recording head described in claims 16 and 17.

In the above embodiment, the shape of the tip of the sound collector 10 is flat, but the shape is not limited to this, and it may be concave or similar to the lens surface of the Fresnel lens. For example, another shape suitable for focusing ultrasonic waves may be used. Further, in the above embodiment, the head for an inkjet printer has been described as an example that is actually used, but the present invention is not limited to this, and may be applied to other products that use an inkjet method.

Further, in the above-mentioned embodiment, the liquid to be granulated has been described by taking an ink liquid made of pure water as an example. However, the liquid is not limited to this, a liquid having a higher viscosity, a pigment or other granularity is used. A wide variety of liquids may be granulated and caused to fly, including liquids having For example, a color filter material in a liquid crystal display device, an EL light emitting material in an organic EL device, a fluorescent material in an electron emitting device, a migration body in an electrophoretic display device, a liquid metal material in forming metal wiring, and a small cell between two substrates. In a spacer forming method of forming a large number of particulate spacers to form a gap, a liquid into which a particle material forming the spacer is introduced can be considered.

[0046]

As described above, according to the liquid granulating apparatus of the present invention, a part including the tip of the sound collector is arranged in the liquid chamber, and the other part is arranged more than the liquid in the liquid chamber. Since it is arranged in a medium with a low acoustic impedance, the transmittance of energy into the air in other parts is higher in the liquid in the liquid chamber, so the part including the tip of the sound collector The energy loss (vibration wave energy that penetrates the liquid) is greater than the rest. That is, as compared with the case where the entire sound collector is immersed in the ink liquid, the energy loss in the portion exposed in the air becomes smaller, so that it is possible to improve energy efficiency.

Further, since the predetermined position of the sound collecting member is supported by the predetermined supporting means to stabilize the posture of the sound collecting member, the vibration of the sound collecting member is less hindered as compared with the case where the sound collecting member is not supported. Therefore, it becomes possible to stabilize the vibration. Furthermore, since the vibration supplying means that is in close contact with the sound collector is not fixed to anything other than the sound collector, the vibration of the sound collector is not obstructed more than when it is fixed, so that the vibration can be stabilized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first configuration example of a liquid granulation device according to the present invention.

FIG. 2 is a diagram showing an example in which a recording head for an inkjet printer is configured as an actual application example in which a plurality of first configuration examples 1 of a liquid granulating device are used.

FIG. 3 is a diagram showing a second configuration example of the liquid granulation device.

FIG. 4 is a diagram showing an example of node positions of a sound collector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st structural example of a liquid granulation apparatus, 2 ... Heads for inkjet printers 2, 3 ... 2nd structural example of a liquid granulation apparatus, 10 ... Sound collector, 10a ...
Upper part of sound collector, 10b ... Lower part of sound collector, 11 ... Oscillating wave supply part, 11a ... Piezoelectric element, 11b ... Signal generating part, 12 ... Liquid chamber, 13 ... Support Department, 14 ...
Nozzle plate, 15 ... Nozzle

Claims (17)

[Claims] 1. A sound collector having a predetermined shape designed to have a length in the vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to the self, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A liquid granulating device for granulating a part of the liquid in the liquid chamber and flying the liquid, wherein a part including the tip of the sound collector is disposed in the liquid chamber,
A liquid granulating device, characterized in that the other part is arranged in a medium having a lower acoustic impedance than the liquid. 2. A sound collector having a predetermined shape, the length of which in the direction of propagation of the vibration wave is designed to be an integral multiple of a half wavelength of the vibration wave supplied thereto, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A liquid granulating device for granulating a part of the liquid in the liquid chamber and flying the liquid, wherein a part including the tip of the sound collector is disposed in the liquid chamber,
A liquid granulating device, characterized in that the other part is disposed outside the liquid chamber. 3. The position part of the sound collector where the displacement of the vibration wave propagating in the sound collector is zero, is supported on the support body side through a support means. 2. The liquid granulating device according to 2. 4. The liquid granulating apparatus according to claim 3, wherein the inside and outside of the liquid chamber are fractionated by utilizing the supporting means. 5. The bottom part of the sound collector is used as a supply part of the vibration wave from the vibration wave supply means, and the supply part is in a non-contact state with the support body side. The liquid granulating apparatus according to any one of claims 1 to 4. 6. The vibrating wave supply means comprises a piezoelectric element and a signal generating section for supplying a drive signal to the piezoelectric element, as claimed in any one of claims 1 to 5. Liquid granulator. 7. A sound collector having a predetermined shape designed to have a length in the vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to the self, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A liquid granulating device for granulating and flying a part of the liquid in the liquid chamber by means of supporting a position part of the sound collecting body where the displacement of the vibration wave propagating in the sound collecting body becomes 0. A liquid granulating device characterized in that it is supported on the body side through a supporting means. 8. The bottom part of the sound collector is used as a supply part of the vibration wave from the vibration wave supply means, and the supply part is in a non-contact state with the support body side. 7. The liquid granulating device according to 7. 9. The liquid granulation apparatus according to claim 7, wherein the inside and outside of the liquid chamber are fractionated by utilizing the supporting means. 10. A sound collector having a predetermined shape designed to have a length in a vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to the self, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A liquid granulating device for granulating a part of the liquid in the liquid chamber and flying the liquid, wherein the bottom part of the sound collector serves as a supply part of the vibration wave from the vibration wave supply means, and The liquid granulation device is characterized in that the supply unit is in a non-contact state with the support side. 11. The liquid granulating apparatus according to claim 10, wherein the vibration wave supply unit includes a piezoelectric element and a signal generator that supplies a drive signal to the piezoelectric element. 12. A sound collector having a predetermined shape, the length of which in the direction of propagation of the vibration wave is designed to be an integral multiple of a half wavelength of the vibration wave supplied thereto, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A method of manufacturing a liquid granulating device for granulating a part of the liquid in the liquid chamber and flying the liquid, wherein a part including a tip end portion of the sound collector is disposed in the liquid chamber,
A method for manufacturing a liquid granulating device, characterized in that the other part is disposed in a medium having a lower acoustic impedance than the liquid. 13. A sound collector having a predetermined shape designed to have a length in the vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to the self, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A method of manufacturing a liquid granulating device for granulating a part of the liquid in the liquid chamber and flying the liquid, wherein a part including a tip end portion of the sound collector is disposed in the liquid chamber,
A method of manufacturing a liquid granulating device, characterized in that another part is disposed outside the liquid chamber. 14. A sound collector having a predetermined shape designed to have a length in the vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to the self, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A method for manufacturing a liquid granulating device for granulating and flying a part of the liquid in the liquid chamber by means of: a displacement of any one of the vibration waves of an integral multiple wavelength propagating in the sound collector. A method of manufacturing a liquid granulating apparatus, characterized in that a position portion of the sound collector which becomes 0 is supported by a predetermined supporting means. 15. A sound collector having a predetermined shape designed to have a length in the vibration wave propagation direction that is an integral multiple of a half wavelength of the vibration wave supplied to itself, and the vibration wave is supplied to the sound collector. And a liquid chamber for accumulating a predetermined liquid. The vibrating wave is converged by supplying the vibrating wave to the sound collector by the vibrating wave supplying means. A method for manufacturing a liquid granulating device for granulating and flying a part of the liquid in the liquid chamber by means of the method, wherein the bottom of the sound collector serves as a supply part of the vibration wave from the vibration wave supply means. At the same time, the supply unit is in a non-contact state with the support side, and the method for manufacturing a liquid granulating apparatus. 16. The method according to any one of claims 1 to 11.
An ink jet recording head comprising the liquid granulating device according to the item. 17. An ink jet printer comprising the ink jet recording head according to claim 16.