JPH10250075A - Method and unit for jetting recording liquid for printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability and mass productivity by varying the pressure in a liquid chamber through deformation of a thin film shape-memory alloy taking place during phase variation process and jetting a recording liquid thereby enhancing the density of nozzle and the resolution while suppressing the jamming of nozzle through increase of ink jet pressure. SOLUTION: A space section 11 is formed vertically through a substrate 10 and the upper part thereof is covered with a thin film shape-memory alloy 12 which is then mounted, immediate thereon, with a channel plate 13 provided with a chamber 14 for containing a recording liquid 20. The channel plate 13 is provided, in the center thereof, with a main channel 15 for passing the recording liquid 20 and, on one side thereof, with a liquid injection port 17 communicating with the main channel 15 and a nozzle 19 corresponding to the liquid chamber 14 is made in a nozzle plate 18 provided above the channel plate 13. When a current is fed from a power supply section to electrodes coupled to the opposite ends of the thin film shape-memory alloy 12, heat is generated by its own resistance and the temperature is raised. Consequently, the shape-memory alloy 12 is flattened while being changed to mother phase and the pressure in the liquid chamber 14 is raised. When current supply is interrupted, it is reset to expanded state and the pressure is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid ejecting apparatus for a printer head and a method thereof. By doing so,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid ejecting apparatus and method for a printer head which can be downsized and whose manufacturing process is simplified.

[0002]

2. Description of the Related Art A widely used printer head is a DOD (Drop and Demand) system. This DOD method does not need to charge or deflect the recording liquid droplets, does not require high pressure, and can easily print by ejecting the recording liquid droplets immediately under atmospheric pressure. Therefore, it is gradually being used. Typical ejection principles include a heating ejection method using a resistor and a vibration ejection method using a piezoelectric element.

FIG. 1 is for explaining the principle of the heating type jetting method.
There is an ejection port a2 facing the recording material from the chamber a1, and a chamber a on the opposite side of the ejection port a2 is provided.
A resistor a3 is buried in one bottom portion to cause expansion of air. Therefore, the bubbles expanded by the resistance heating push the recording liquid inside the chamber a1 to the ejection port a2, and the recording liquid is ejected toward the recording material by the force.

FIG. 2 is for explaining the principle of the vibration type ejection method using a piezoelectric element. Similarly, there is a chamber b1 in which a recording liquid is provided.
There is an ejection port b2 from 1 to the recording material, and a piezoelectric element is buried in the bottom opposite to the ejection port to generate vibration.

As described above, when the piezoelectric element b3 vibrates at the bottom of the chamber b1, the recording liquid is ejected by the ejection port b by vibrating force.
The recording liquid is ejected to the recording material by the vibration force. Since the ejection method using the vibration of the piezoelectric element does not use heat, there is an advantage that the selection range of the recording liquid is large.

Further, a conventional printer head uses a shape memory alloy to discharge a recording liquid. JP 57
-203177, JP-A-63-57251, JP-A-4-
247680, JP-A-2-265752, JP-A-2-3
08466, JP-A-3-65349 discloses an embodiment of a printer head using a shape memory alloy.
The conventional embodiment has a configuration in which a large number of shape memory alloys having different phase transformation temperatures and different thicknesses are combined to bend and deformed, and are configured to be bent and deformed by a combination of an elastic member and a shape memory alloy. And others.

[0007]

However, the above-mentioned heating type jet method has a problem that a chemical change occurs due to heating of the recording liquid, and such recording liquid adheres to the inner surface of the ejection port a2 to cause clogging. However, there is a drawback that the life of the heating resistor is short, and the storage stability of the document is poor because a water-soluble recording liquid must be used.

[0008] In addition, the above-described injection method using the vibration of the piezoelectric element has a problem in that mass production is poor because the processing of the piezoelectric element is difficult, and particularly, the work of attaching the piezoelectric element to the bottom of the chamber b1 is difficult.

Further, the conventional printer head using a shape memory alloy has problems that it is difficult to reduce the size of the head, the density and resolution of the nozzles are low, the manufacturing is difficult, and the mass productivity is poor. In addition, the shape memory alloy used is not a thin film but a thick film with a thickness of 50 μm or more. Therefore, power consumption during heating is large, cooling time is long, operating frequency is low, and printing speed is slow. There's a problem.

The present invention has been developed in order to solve the above-mentioned various problems in the prior art. It is an object of the present invention to provide a thin film shape memory alloy having a liquid chamber formed by a deformation occurring during a phase change process. By changing the pressure to eject the recording liquid, the pressure at which the shape memory alloy is generated increases, and nozzle clogging is reduced. Since the amount of deformation of the thin film is large, the resolution is improved by reducing the size of the thin film shape memory alloy and increasing the density of the nozzles. Accordingly, an object of the present invention is to provide a recording liquid ejecting apparatus for a printer head and a method therefor, which can improve the mass productivity because the displacement amount can be obtained.

[0011]

In order to achieve the above object, a recording liquid ejecting apparatus for a printer head according to the present invention comprises:
A thin-film shape memory alloy whose shape changes according to a temperature change, a power supply unit for generating a temperature change of the thin-film shape memory alloy, and a liquid chamber installed on one side of the thin-film shape memory alloy for storing a recording liquid A flow path plate having a flow path formed so as to allow the recording liquid to flow into one side of a wall surrounding the liquid chamber; and a thin film shape memory alloy provided on the flow path plate. A nozzle plate formed with a nozzle having an area smaller than the area of the liquid chamber of the flow path plate so that the recording liquid is ejected in the form of droplets when the shape changes.

The present invention solves the disadvantages of both the method using the existing piezoelectric element and the method using air expansion by heating, and the method using the existing shape memory alloy. A recording liquid that forms a thin film shape memory alloy on a substrate, etches a part of the substrate, forms a space where the thin film shape memory alloy can vibrate, and forms droplets by vibration of the thin film shape memory alloy An injection device is provided.

[0013] Using a semiconductor manufacturing process, a shape memory alloy is deposited on a substrate and then heat-treated to form a thin film shape memory alloy. Therefore, the shape memory alloy has a flat shape in the matrix state. The deposited thin film shape memory alloy can maintain the residual compressive stress with martensite, and can change the magnitude of the residual compressive stress depending on the deposition conditions, heat treatment temperature, time, and the like. When a space is formed by etching a part of the substrate, the thin film shape memory alloy is bent and deformed by a buckling phenomenon due to residual compressive stress. When the thin film shape memory alloy is heated, the thin film shape memory alloy becomes a mother phase and tends to change to a flat state. At this time, the volume of the liquid chamber is reduced and the recording liquid is jetted. At the time of cooling, bending deformation occurs due to the residual compressive stress, and at this time, the recording liquid is refilled. Such a process is repeated to continuously eject the recording liquid.

The present invention has a simple structure, a thin film shape memory alloy is produced by a semiconductor thin film manufacturing process and substrate etching, and the displacement of the thin film shape memory alloy required for jetting a recording liquid using residual compressive stress. Can be easily obtained, thereby improving mass productivity. Further, since the amount of deformation can be easily adjusted by changing the magnitude of the residual compressive stress, a large amount of displacement can be obtained, and the area of the thin film shape memory alloy can be reduced. Therefore, the size of the head can be reduced, and high resolution can be achieved by increasing the density of the nozzles.

Since a thin film shape memory alloy is used, the power consumption during heating is greatly reduced, and the cooling time is very short.
In addition, when the recording liquid is ejected and returns to the state of bending deformation due to residual compressive stress, no residual vibration occurs, so that
Stable ejection of the recording liquid can be performed. Therefore, the operating frequency can be increased, that is, the printing speed can be improved.

[0016]

FIG. 3 is an exploded perspective view of an ejection device according to one embodiment of the present invention, and FIG. 4 is a perspective view showing a flow of a recording liquid according to one embodiment of the present invention. In the ejecting apparatus of the present invention, in order to increase the resolution, a large number of nozzles 19 for ejecting the recording liquid 20 are arranged vertically and horizontally, and the thin film shape memory alloy 12 for substantially ejecting the recording liquid 20 is used for each nozzle 19 And one-to-one.

That is, a large number of spaces 11 penetrating in the vertical direction are formed before and after the substrate 10, and a large number of thin film shape memory alloys 12 which are connected to the upper portion of the substrate 10 and close each space 11 are provided. A flow path plate 13 covering an upper portion of the substrate 10;
In the flow path plate 13, a liquid chamber 14 for storing the recording liquid 20 is formed immediately above each of the thin film shape memory alloys 12. A main channel 15 through which the recording liquid 20 flows is provided at the center of the channel plate 13, and the main channel 15 and the corresponding liquid chamber 14 communicate with each other through a channel 16. The flow path plate 1 is provided on one side of the substrate 10.
3 has a liquid inlet 17 communicating with the main flow path 15 on one side, and the recording liquid 20 is supplied to the main flow path 15 side.

Further, a nozzle plate 18 is provided on the upper part of the flow path plate 13, and the nozzle plate 18 is
A number of nozzles 19 corresponding to each of the liquid chambers 14 formed are formed. Further, each nozzle 19 corresponds to the thin film shape memory alloy 12 exposed to the corresponding liquid chamber 14, and when the thin film shape memory alloy 12 is deformed, the pressure of the corresponding liquid chamber 14 changes and the recording liquid 20 drops. In this state, the ink is ejected onto the paper through each nozzle 19.

The thin film shape memory alloy 12 undergoes a continuous phase change due to a temperature change.
0 is ejected through each nozzle 19 in the form of a droplet.

FIGS. 6A to 6D are side sectional views of an injection device according to one embodiment of the present invention, which are extracted from one thin film shape memory alloy. Thin film shape memory alloy 12
When heated above the set temperature in the initial state where it has expanded to the opposite side of the nozzle 19, it tends to become flat while changing to the parent phase. At this time, as the internal pressure of the liquid chamber 14 increases and is compressed, the recording liquid 20 is ejected through the nozzle 19. When the temperature of the thin film shape memory alloy 12 falls below the set temperature, the thin film shape memory alloy 12 is restored to the bending deformation state by the residual compressive stress, the internal pressure of the liquid chamber 14 is reduced, and the recording liquid 20 is changed by the capillary action of the nozzle 19 and the suction force. It flows into the interior of the chamber 14. Thereafter, the above process is continuously repeated for printing.

The thin film shape memory alloy 12 is heated by a power supply 21 as shown in FIG.
That is, when a current flows from the power supply unit 21 to the electrodes 21a coupled to both ends of the thin film shape memory alloy 12, the thin film memory shape alloy 12 generates heat due to self-resistance, rises in temperature, and becomes flat while changing to a mother phase. Further, when the current of the power supply unit 21 is cut off, the thin film shape memory alloy 12 returns to its original expanded state due to residual compressive stress while cooling naturally. Also, as shown in FIG.
The heater 21b for heating by the current from the thin film shape memory alloy 12 is provided on one side surface of the thin film shape memory alloy 12.
Can be heated.

As such a thin film shape memory alloy 12, a shape memory alloy which undergoes a phase change and is deformed by temperature can be used. The material is mainly composed of titanium and nickel, and the thickness thereof is about 0.1 mm. It is about 3 μm to 5 μm. Also, a thin film shape memory alloy 1 made of a shape memory alloy
2 has directionality depending on the manufacturing method. 8 and 9 are a process diagram and a block diagram showing a method of manufacturing a one-way thin film shape memory alloy according to the present invention, and FIGS. 3 and 6 show the use of a one-way thin film shape memory alloy. A step 100 of depositing a thin film shape memory alloy 12 on a substrate 10 made of a material such as silicon is obtained. For the vapor deposition, a sputtering method and a laser ablation method can be mainly used.

Then, when the film is heat-treated at a certain temperature for a certain time to be crystallized, a stage 101 is formed from the mother phase to a plate-like shape. Thereafter, when the matrix is cooled to a martensite finish temperature (Mf) of about 40 ° C. to 70 ° C., the matrix becomes martensite and a step 102 in which residual compressive stress exists in the thin film shape memory alloy 12 is obtained.

When the thin film shape memory alloy 12 is etched, a space portion 11 is formed in the substrate 10 made of a silicon wafer, and a step 103 in which the thin film shape memory alloy 12 is exposed to the outside is obtained. The alloy 12 is bent downward (or upward) by the residual compressive stress, and a step 104 as shown in FIG. 6A is obtained.
When the temperature of the thin-film shape memory alloy 12 bent and deformed by martensite is raised to a set temperature, that is, about 50 ° C. to 90 ° C., which is the parent phase end temperature (Af), the thin-film shape memory alloy 12 is transformed into a parent phase, Thus, the step 105 in which the recording liquid 20 is ejected in a flat state is obtained. Further, when the thin film shape memory alloy 12 is cooled to be martensite, the thin film shape memory alloy 12 is bent and deformed by the residual compressive stress, and the recording liquid 20 is refilled into the liquid chamber 14, and the thin film shape memory alloy 12 A step 107 for printing by repeating the steps 105 and 106 according to the temperature change is obtained.

FIGS. 10 and 11 are a process diagram and a block diagram showing a method for manufacturing a two-way thin film shape memory alloy according to the present invention. When the thin film shape memory alloy 12 is heat-treated at a certain temperature for a certain period of time in the chamber 22 and crystallized, a stage 200 to be a parent phase is obtained. Thereafter, the thin-film shape memory alloy 12 is heated to a martensite finish temperature (Mf) of about 40 ° C.
Upon cooling to ７０70 ° C., a stage 201 is obtained in which the parent phase changes to martensite. In addition, a step 202 of applying an external force to deform the martensite within a range where plastic slip does not occur is obtained. Thereafter, when the thin-film shape memory alloy 12 is heated to 50 ° C. to 90 ° C., which is the parent phase end temperature (Af), a step 203 in which the thin film shape memory alloy becomes flat while becoming a parent phase is obtained.

The above steps 201, 202, 20
3 is repeated several times to learn the thin-film shape memory alloy 12. In the learning step 204, when the thin-film shape memory alloy 12 is lowered to the martensite end temperature (Mf), deformation occurs even without external force. A step 205 is generated which occurs. Then, the thin film shape memory alloy 12 is heated to a matrix end temperature (A
When heated to f), a step 206 is obtained in which the thin film shape memory alloy 12 is flattened and the recording liquid 20 is jetted. Further, when the thin film shape memory alloy 12 is cooled to become martensite, it is bent and deformed by itself, and the recording liquid 20 is discharged into the liquid chamber 14.
207, which is replenished into the inside, and the thin film shape memory alloy 1
2 repeats the steps 206 and 207 according to the temperature change, and in these processes, a printing step 208 is obtained. That is, the recording liquid 20 is ejected while the thin film shape memory alloy 12 reciprocates in two directions due to a temperature change. Further, since the amount of bending deformation of a bidirectional thin film shape memory alloy is determined by the degree to which an external force is applied during the manufacturing process, a desired amount of displacement can be easily obtained.

Thin film shape memory alloy 12 having bidirectionality
Can be applied to the case of FIG. 6, which is one embodiment of the present invention. For example, after forming the space 11 on one side of the substrate 10, the learned thin film shape memory alloy 12 is bonded to the substrate 10. At this time, the thin film shape memory alloy 12 is
When the temperature is changed, the thin film shape memory alloy 12 is fixed to the space 11
And the recording liquid 20 is ejected.

Further, the thin film shape memory alloy 12 of the present invention becomes flat in the parent phase and bends and deforms in martensite due to a temperature difference. Therefore, as the temperature difference becomes smaller, the frequency (operating frequency) of the thin film 12 increases. I do. Therefore, copper can be added to the alloy of titanium and nickel to reduce the phase change temperature difference. As described above, the shape memory alloy using titanium, nickel, and copper can increase the frequency, that is, the operating frequency of the thin film shape memory alloy 12 by increasing the phase change temperature difference, thereby improving the printing speed.

It is possible to calculate whether or not injection is possible from the thin film memory shape alloy of the present invention configured as described above.

The energy density (W _max ) generated by the thin film shape memory alloy is up to 10 × 10 ⁶ J / m ³ , and the volume (V) of the thin film shape memory alloy is 200 μm × 200 μm
In the case of × 1 μm, assuming that the diameter of the generated droplet is 60 μm, whether or not the thin film shape memory alloy can be ejected is determined as follows. U = U _S + U _K U _S = πR ² γ

(Equation 1) U = energy required to generate a desired droplet of the recording liquid U _S = surface energy of the recording liquid U _K = kinetic energy of the recording liquid R = diameter of the droplet V = velocity of the recording liquid ρ = of the recording liquid Density (1000 kg / m ³ ) γ = Surface tension of recording liquid (0.073 N / m)

If the speed of the desired droplet is 10 m / sec, the required energy (U) is: U = 2.06 × 10 ⁻¹⁰ + 7.07 × 10 ⁻¹⁰ = 9.13
× 10 ^-10 J Maximum energy generated by thin film shape memory alloy W
_max = _Wv · V ( _Wv : energy that can be generated per unit volume of the thin film shape memory alloy J / m ³ , V: volume of the thin film shape memory alloy) W _max = (10 × 10 ⁶ )・ (200 × 200 × 1) = 4 × 10 ^-7 J

When the diameter of the droplet is 100 μm, the required energy U is 3.85 × 10 ⁻⁹ J.

Therefore, since W _max >> U, a droplet having a desired size can be obtained. That is, since the thin film shape memory alloy has an extremely large generating force, it is possible to easily obtain a desired recording liquid droplet.

The displacement of the heating time, the consumed energy and the residual compressive stress according to the embodiment of the present invention are analyzed as follows. An electric current is applied to the thin-film shape memory alloy 12 so that heat is generated by resistance and a phase change is caused by the heat.
2 is heated to 70 ° C., that is, the heating time until the mother phase is obtained and the consumed energy are obtained as follows. Material of thin film shape memory alloy = TiNi Length of thin film shape memory alloy (l) = 400 µm Density (ρ _s ) of thin film shape memory alloy = 6450 kg / m ³ Temperature change (ΔT) = 70-25 = 45 ° C Heat capacity ( Specific heat) (C _p ) = 230 J / kg ° C. Specific resistance of thin film shape memory alloy (ρ) = 80 μ · cm Current (I) = 1.0 A Thin film shape memory alloy width (w) = 300 μm height (t) = 1.0μm heating time (t _h)

(Equation 2) Resistance (R) of thin film shape memory alloy = ρ (1 / w · t) = 1.1Ω Power consumption (I ² R) = 1.1 watt The energy required to generate a droplet is heating time × power consumption = 8.1μJ

Therefore, the energy required for ejecting the recording liquid 20 to generate liquid droplets is about 8.1 μJ, which consumes less energy than the conventional heating method of 20 μJ.

FIG. 12 is a graph showing the relationship between the heating time and the temperature of the thin film shape memory alloy of the present invention. The physical properties for the experiment are shown below. However, the thickness of the thin film shape memory alloy 12 is 1 μm, and the ambient temperature is 25 ° C.

[Table 1]

When the ambient temperature is 25 ° C., after heating to 70 ° C. to change into the parent phase, the time to cool to 30 ° C. is about 2 hours.
It is about 00 μsec, which is about 5 kHz when converted to a frequency. Therefore, the operating frequency of the printer head is about 5 kHz. However, since the temperature at which the deformation is completely completed (the martensite end temperature) is about 45 ° C., there is no need to wait until the temperature drops to 30 ° C., and before that, the recording liquid 20 can be reheated and the recording liquid 20 can be continuously jetted. , 5
The operating frequency can be increased to more than kHz. The higher the operating frequency, the higher the printing speed.

The displacement and restoring force due to the residual compressive stress of the thin film shape memory alloy and itself are analyzed with reference to FIG. 13 as follows. When a = b a = 200 μm Material of thin film shape memory alloy = TiNi Young's modulus (E _m ) of thin film shape memory alloy = 30 GPa Residual compressive stress existing in thin film shape memory alloy = 30 MPa Poisson's ratio (ν) = 0. 3 of thin film shape memory alloy exposed to the space portion 11 length = a thin film shape memory alloy thickness = h _m space 11 in the exposed width of the thin-film shape memory alloy = b thin shape memory alloy of the critical stress (S _cr)

(Equation 3) S _cr = 3.6 MPa Center displacement (δ _m ) of thin film shape memory alloy:

(Equation 4) δ _s = 6.2 μm The total energy (U _m ) generated when the thin film shape memory alloy buckles is

(Equation 5) = 2.8 × 10 ^-10 J

After the recording liquid is sprayed, the total energy generated when the thin film shape memory alloy buckles changes into a restoring force (P) that causes bending deformation of the thin film shape memory alloy,
The restoring force is as follows. Um = P · ΔV Volume change (ΔV) = (δ _s · α ₂ ) /4=6.2×10 ⁻¹⁴ m ³ Restoring force (P) = 4.5 kPa

Assuming that one half of the total volume change caused by buckling of the thin film shape memory alloy has been ejected, a droplet of 39 μm is formed. The amount of displacement with respect to the thickness and size of the thin film shape memory alloy is as shown in the table below, and the unit is μm.

[Table 2]

FIG. 14 is a sectional view of an injection device according to another embodiment of the present invention. The present invention will be described using the same reference numerals for the same components as those in FIG. In another embodiment of the present invention, the flow path plate 13 and the nozzle plate 18
This is an extract of the bonding state of one thin film. Space 1 penetrating vertically through substrate 10
1 is formed, and includes a thin film shape memory alloy 12 bonded to an upper portion of the substrate 10 and covering the space portion 11. The substrate 10
A liquid chamber 14 for accommodating the recording liquid 20 is formed in the flow path plate 13 corresponding to the space 11.

A nozzle plate 18 is provided at the lower portion of the flow path plate 13.
The nozzle 19 corresponding to the liquid chamber 14 formed in 3 is formed. The nozzle 19 corresponds to the thin film shape memory alloy 12 exposed on the liquid chamber 14 side. When the thin film shape memory alloy 12 is deformed, the pressure of the liquid chamber 14 changes and the recording liquid 20 is changed to a liquid state. The ink is ejected onto the sheet via the nozzle 19.

The other embodiment of the present invention configured as described above has a thin film shape memory alloy structure similar to that of the first embodiment of the present invention. At this time, the thin-film shape memory alloy 12 has one-way and two-way properties depending on the manufacturing process, undergoes a phase change due to a temperature change, and is deformed. In this process, the thin-film shape memory alloy 12 is stored in the liquid chamber 14 and the space 11. The recording liquid 20 is ejected to the sheet via the nozzle 19 in a droplet state. Further, in another embodiment of the present invention, the recording liquid 20 is stored in the space 11 formed in the substrate 10, and the liquid chamber 15 and the flow path 16 can be easily formed in the substrate 10.

[0044]

As described above, according to the present invention,
The thin film shape memory alloy for injecting the recording liquid undergoes a phase change due to a temperature change, and is deformed in this process to eject the recording liquid. Further, since the thin film shape memory alloy has a large displacement, each space formed in the substrate and each liquid chamber formed in the flow path plate can be made smaller, so that the overall size of the printer head becomes smaller, and the size of the nozzle becomes smaller. This is effective for increasing the density and realizing high resolution. In addition, since the generated force is large, the force for pushing out the recording liquid is increased and the clogging of the nozzle is reduced, so that the reliability is improved, and the droplet size of the recording liquid is sufficiently reduced, so that the image quality is improved. Is advantageous. Further, since the drive voltage is 10 volts or less, the design and manufacture of the drive circuit are easy. Using existing semiconductor and etching processes, a thin film shape memory alloy that plays the role of a diaphragm can be easily formed on a substrate composed of silicon, glass, a metal plate, a polymer, etc., thus improving mass productivity. Thus, the structure can be simplified.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional heating type injection device.

FIG. 2 is a sectional view of a conventional piezoelectric element type injection device.

FIG. 3 is an exploded perspective view of an injection device according to an embodiment of the present invention.

FIG. 4 is a perspective view illustrating a flow of a recording liquid according to an embodiment of the present invention.

5 (a) and 5 (b) are front sectional views of an injection device according to an embodiment of the present invention.

6 (a), (b), (c) and (d) are cross-sectional views showing an operation process of the injection device according to one embodiment of the present invention.

FIG. 7 is a graph showing a phase change of the thin film shape memory alloy of the present invention.

FIG. 8 is a process chart showing a method for producing a one-way thin film shape memory alloy according to the present invention.

FIG. 9 is a block diagram illustrating a method for manufacturing a one-way thin film shape memory alloy according to the present invention.

FIG. 10 is a process chart showing a method for producing a two-way thin film shape memory alloy according to the present invention.

FIG. 11 is a block diagram illustrating a method for manufacturing a two-way thin film shape memory alloy according to the present invention.

FIG. 12 is a graph showing the relationship between the heating time and the temperature of the thin film shape memory alloy of the present invention.

FIG. 13 is a sectional view showing the size of the thin film shape memory alloy of the present invention.

FIGS. 14 (a), (b), (c) and (d) are cross-sectional views showing the operation process of an injection device according to another embodiment of the present invention.

[Explanation of symbols]

 a1, b1 chamber a2, b2 injection port a3 resistance b3 piezoelectric element 11 space section 12 thin film shape memory alloy 13 flow path plate 14 liquid chamber 15 main flow path 16 flow path 17 liquid injection port 18 nozzle plate 19 nozzle 20 recording liquid 21 power supply Part 21a electrode 21b heater

Claims (18)

[Claims] 1. A thin film shape memory alloy (12) whose shape changes according to a temperature change, a power supply unit (21) for generating a temperature change of the thin film shape memory alloy (12), and a thin film shape memory alloy (12). ) To form a liquid chamber (14) for storing the recording liquid (20), and the recording liquid (20) is provided on one side of a wall surrounding the liquid chamber (14). A flow path plate (13) having a flow path (16) formed therein so that the liquid flows into the recording liquid (20) when the thin film (12) changes shape. A nozzle plate (18) formed with a nozzle (19) having an area smaller than the area of the liquid chamber (14) of the flow path plate (13) so that the liquid is ejected in the form of droplets. Recording liquid ejection device for printer head. 2. The apparatus according to claim 1, wherein said thin film shape memory alloy is a shape memory alloy containing titanium and nickel as main components. 3. The shape memory alloy according to claim 2, wherein the thin film shape memory alloy is a shape memory alloy to which copper is further added in order to reduce the phase change temperature difference and increase the operating frequency. Recording liquid ejection device for printer head. 4. The method according to claim 1, wherein the thin film shape memory alloy (12) has a thickness of 0.1 mm.
2. The apparatus according to claim 1, wherein the apparatus has a thickness of 3 to 5 [mu] m. 5. The power supply unit (21) generates heat by self-resistance of the thin film shape memory alloy (12).
The recording liquid ejecting apparatus according to claim 1, further comprising electrodes (21a) coupled to both ends of the thin film shape memory alloy (12). 6. A heater (21) formed on one side of the thin film shape memory alloy (12) and heated by an electric current from the power supply unit (21).
The recording liquid ejecting apparatus for a printer head according to claim 1, further comprising: b). 7. A substrate (10) provided below the thin film shape memory alloy (12) and having a space (11) in which the thin film shape memory alloy (12) can change its shape. The recording liquid ejecting apparatus for a printer head according to claim 1. 8. The apparatus according to claim 7, wherein said substrate is made of a silicon material. 9. The area where the thin film shape memory alloy (12) is exposed to the space (11) and substantially changes its shape is:
The recording liquid ejecting apparatus according to claim 7, wherein the width (b) is 100 m to 500 m and the length (a) is 100 m to 300 m. 10. When the thin film shape memory alloy (12) is heated to the parent phase end temperature and changes to the parent phase, it forms a flat plate and the recording liquid (20) is jetted through the nozzle (19). The recording liquid (20) is replenished into the liquid chamber (14) by cooling to a martensite end temperature or lower and transforming into martensite, thereby bending and deforming due to residual compressive stress. Recording liquid ejecting device for printer head. 11. The mother phase end temperature is about 50 ° C. to 90 ° C.
And the martensite end temperature is about 40 ° C. to 70 ° C.
The recording liquid ejecting apparatus for a printer head according to claim 10, wherein the temperature is ℃. 12. The recording of a printer head according to claim 10, wherein the time from heating to said matrix to cooling to martensite is about 200 μsec or less, and the operating frequency is 5 kHz or more. Liquid injection device. 13. When the thin film shape memory alloy (12) is heated to the parent phase end temperature and changes to the parent phase, it becomes a flat plate and the recording liquid (20) is jetted through the nozzle (19). The recording liquid (20) is replenished into the liquid chamber (14) by bending deformation by learning that the recording liquid changes to martensite by cooling to a martensite end temperature or lower. 2. A recording liquid ejecting apparatus for a printer head according to claim 1. 14. When the thin-film shape memory alloy (12) is martensite, learning is performed by applying an external force several times, and then when the film is cooled to a martensite end temperature or lower, martensite is formed in a specific direction. 14. The apparatus according to claim 13, wherein the apparatus has a desired displacement. 15. The mother phase end temperature is about 50 ° C. to 90 ° C.
And the martensite end temperature is about 40 ° C. to 70 ° C.
14. The recording liquid ejecting apparatus for a printer head according to claim 13, wherein the temperature is ° C. 16. The recording of a printer head according to claim 13, wherein the time from heating to said matrix to cooling to martensite is about 200 μsec or less, and an operation frequency is 5 kHz or more. Liquid injection device. 17. A thin film shape memory alloy (1) is formed on a substrate (10).
2) depositing (100); heat-treating and crystallizing the thin film shape memory alloy (12) to store a flat state in the mother phase (101); ) Is cooled to martensite and the step (10) having residual compressive stress
2) etching the substrate (10) to expose a portion of the thin film shape memory alloy (12);
3), a step (104) in which the exposed portion of the thin film shape memory alloy (12) is bent and deformed by residual compressive stress, and when the thin film shape memory alloy (12) is heated to become a parent phase, it becomes flat. Injecting the recording liquid (20) (10
5) When the thin film shape memory alloy (12) is cooled to be martensite, it is bent and deformed by residual compressive stress, and the recording liquid (20) is refilled into the liquid chamber (14) (10).
6) and a step (107) of repeating the steps (105) and (106) according to a temperature change of the thin film shape memory alloy (12) to perform printing (107). 18. Depositing a thin film shape memory alloy (12) and then heat treating it to crystallize (200), and cooling the thin film shape memory alloy (12) to martensite (201) Applying an external force to the thin film shape memory alloy (12) to bend and deform (202); heating the thin film shape memory alloy (12) so that the thin film shape memory alloy (12) becomes flat in a parent phase (203); Cooling, deformation, heating steps (201), (202),
(203) was repeated several times to obtain the thin film shape memory alloy (1).
2) learning (204); cooling the thin film shape memory alloy (12) after the learning step (204) to become martensite; When the memory alloy (12) is heated and becomes a parent phase, the memory alloy (12) becomes flat and ejects the recording liquid (20) (20).
6), when the thin film shape memory alloy (12) is cooled to become martensite, the recording liquid (20) is replenished into the liquid chamber (14) by bending deformation (207); A step (208) of repeatedly performing the steps (206) and (207) according to a temperature change of the memory alloy (12), and printing (208).