KR100221460B1 - Recording liquid ejecting apparatus and method thereof of print head - Google Patents

Abstract

The present invention relates to a recording liquid ejecting apparatus for a printhead and a method thereof.

The present invention provides a second thin film that can control the amount of deformation and restoring force of the diaphragm by using a semiconductor thin film manufacturing process to increase the restoring force when the thin film mold restoring alloy is restored to a bending deformation state in the cooling process. In this case, the time required for the diaphragm to be restored to the bending deformation after the injection of the recording liquid is shortened, the operating frequency is increased, and the printing speed is increased, and the strength of the diaphragm is increased to reduce the risk of damage due to external impact. A recording liquid jetting apparatus and a method thereof, in particular, at least one or more second thin films coupled to a thin film shape alloy of a shape memory alloy material and a thin film shape inhibitor alloy which are changed in shape according to a temperature change to control a shape change amount thereof. A diaphragm having a diaphragm, a power supply unit for generating a temperature change of the thin film-type storage alloy, and the thin film shape A liquid chamber is formed on the storage alloy to store the recording liquid, and a flow path plate is formed so that the recording liquid flows into one side of the wall surrounding the liquid chamber, and the thin film is formed on the flow path plate. The nozzle plate is characterized in that the nozzle plate having a smaller area than the liquid chamber area of the flow path plate is formed so that the recording liquid can be ejected in the form of droplets.

Description

Record liquid jetting apparatus of printhead and its method

1 is a cross-sectional view of a conventional heated injector.

2 is a cross-sectional view of a conventional piezoelectric element injector.

Figure 3 is an exploded perspective view of the injector of one embodiment of the present invention.

4 is a perspective view showing the recording liquid flow in one embodiment of the present invention.

5a, b, c is a front sectional view of the injector of the embodiment of the present invention.

6 is a side cross-sectional view of the injector of one embodiment of the present invention, wherein a to b show before and after operation.

7 is a diagram showing the phase change of the thin film-type storage alloy of the present invention.

8 is a process chart showing a method of manufacturing a diaphragm according to the present invention.

9 is a block diagram showing a method of manufacturing a diaphragm according to the present invention.

10 is a diagram showing the heating time and temperature of the thin film of the present invention.

11 is a cross-sectional view showing the size of the diaphragm of the present invention.

12 is a cross-sectional view of the injector of another embodiment of the present invention, in which a to c show before and after operation.

13 is a sectional view showing another embodiment of the injection device.

14 is a sectional view showing another embodiment of the injection device.

* Explanation of symbols for main parts of the drawings

10 substrate 11 space part

12: vibrating tube 12a: thin-film shape memory alloy

12b: second thin film 12c: heat dissipation film

13: Europan 14: liquid chamber

16: Euro 18: nozzle plate

19: nozzle 20: recording liquid

21: power supply 21a: electrode

21b: heater 100: the second thin film forming step

101: diaphragm forming step 102: heat treatment step

103: cooling step 104: etching step

105: bending deformation step 106: recording liquid injection step

107: recording solution replenishment step 108: printing step

The present invention relates to a recording liquid injector for a printhead and a method thereof, and more particularly, to a diaphragm vibrating according to a temperature change of a thin film-type retaining alloy so that the pressure in the liquid chamber is controlled, and a second thin film having residual compressive stress. Is deposited on the thin film-type memory alloy so that the deformation of the diaphragm can be easily adjusted and the restoring force can be controlled, so that the operating frequency is increased, the printing speed can be improved, the size can be made small, and the structure is simple and the semiconductor thin film manufacturing process is used. The present invention relates to a recording liquid ejecting apparatus for a printhead having excellent properties and a method thereof.

In general, a widely used printhead uses a DoD On Demand (DOD) method. This DOD method is increasingly used because it does not need to charge or deflect recording liquid droplets, does not require high pressure, and can easily print by spraying the recording liquid droplets under atmospheric pressure. Typical spraying principles include a heating spray method using a resistance and a vibration spray method using a piezo-electric.

FIG. 1 is for explaining the principle of the heating jetting method, and there is a chamber a1 in which recording liquid is incorporated, and there is an injection port a2 from the chamber a1 toward the recording material, At the bottom of the chamber a1, the resistor a3 is embedded to induce expansion of air. Therefore, the bubble expanded by resistance causes the recording liquid in the chamber a1 to be pushed out to the injection port a2, and the recording liquid is ejected toward the recording material by the force.

However, this heating spray method causes a chemical change since the recording liquid is heated to heat, and the recording liquid adheres to the inner diameter of the injection hole (a2), causing clogging, and also has a short lifespan of the heat generating resistor. Documents need to be used, which results in poor document retention.

2 is for explaining the principle of the vibrating injection method by the piezoelectric element, there is also a chamber (b1) in which the recording liquid is built, there is an injection port (b2) from the chamber (b1) toward the recording material, Piezoelectric elements (Piezo Transducer) is embedded in the bottom opposite the injection port is configured to cause vibration.

As described above, when the piezoelectric element b3 causes vibration at the bottom of the chamber b1, the recording liquid is pushed out to the injection hole b2 by the vibration force, and thus the recording liquid is transferred to the recording material by the vibration force. To be sprayed.

As the spraying method by vibrating the piezoelectric element does not use heat, there is a wide range of choice of the recording liquid, but it is difficult to process the piezoelectric element, and in particular, the operation of attaching the piezoelectric element to the bottom of the chamber b1 is difficult. Since it is difficult, there exists a problem that mass productivity falls.

Also, in the conventional printhead, a shape memory alloy is used to discharge the recording liquid. Japanese Unexamined Patent Publication Nos. 57-203177, 63-57251, Pyeong 4-247680, Pyeong 2-265752, Pyeong 2-308466, and Pyeong 3-65349 disclose examples of printheads in which shape memory alloys are used. . Conventional embodiments include a plurality of shape memory alloys having different phase transformation temperatures and different thicknesses, which are configured to be bent and deformed, and those configured to be bent by a combination of an elastic member and a shape memory alloy.

However, the frit head using the conventional shape memory alloy is difficult to miniaturize the size of the head, the density of the nozzle is low, the resolution is not good, and the aspect is difficult to manufacture. In addition, since the shape memory alloy is implemented as a thick film having a thickness of 50 μm or more without realizing a thin film, the shape memory alloy has a disadvantage in that it is not practical because the power consumption is large and the cooling time is long and the printing speed is low.

In order to solve the various problems as described above, the present inventors have a printhead for selecting a printhead in which the recording liquid is injected while the pressure of the liquid chamber is changed by vibration generated by the temperature change of the thin film-shaped storage alloy. According to the pre-filed printhead, the clogging phenomenon of the nozzle is reduced due to the large actuation force of the thin film-type suppression alloy, and the deformation amount of the thin film-type suppression alloy is large, so that the printhead can be made small, thereby increasing the density of the nozzle and increasing the resolution. It can be increased, and since the thin film type memory alloy can be easily implemented using the semiconductor thin film manufacturing process and the substrate etching process, the mass productivity is increased.

The present invention relates to an improvement of a pre- filed printhead, and an object of the present invention is to bond a second thin film capable of controlling the amount of deformation and restoring force of a diaphragm to a thin film-type inhibiting alloy by using a semiconductor thin film manufacturing process. The restoring force is increased when restoring to the deflection state during the cooling process, thereby shortening the time for the diaphragm to be restored to the deflection state after the injection of the recording liquid, and increasing the operating frequency to increase the printing speed and the strength of the diaphragm. It is to provide a recording liquid jetting apparatus of the printhead and the method of reducing the risk of damage due to external impact by increasing the.

In order to achieve the above object, the recording liquid jetting apparatus of the printhead according to the present invention is coupled to a thin film type alloy and a thin film type alloy of a shape memory alloy material which is always changed according to temperature change, and at least the shape change amount is controlled. A diaphragm made of at least one second thin film, a power supply unit for generating a temperature change of the thin film-type storage alloy, and a liquid chamber installed on the thin film-type storage alloy and storing a recording liquid, and a wall surface surrounding the liquid chamber. A flow path plate in which a flow path is formed so that the recording liquid flows into one side of the flow path plate, and smaller than the liquid chamber area of the flow path plate so that the recording liquid can be sprayed in the form of droplets when the thin film is changed in shape. Its characteristics are that it is provided with the nozzle plate in which the nozzle of area was formed.

The present invention is to solve the disadvantages of the conventional method using the piezoelectric element and the method using the air expansion by heating, and to solve the disadvantages of the conventional method using the shape memory alloy, a thin film on the substrate using a semiconductor thin film manufacturing process By forming a diaphragm composed of a shape memory alloy and a second thin film having a current compressive stress, etching a part of the substrate to form a space in which the diaphragm can vibrate, and implementing a recording liquid injector for forming droplets by vibrating the diaphragm. .

Such an injector is deposited on a substrate by a sputtering method and then heat-treated to form a thin film-type retaining alloy. Therefore, a flat shape is achieved in the mother state. In addition, the second thin film is also configured to be combined with the thin film-type storage alloy using a semiconductor thin film manufacturing process. The deposited second thin film may have a residual compressive stress and may change the magnitude of the residual compressive stress according to a deposition method, a deposition condition, or a material. When a portion of the substrate is etched to form a space part, the diaphragm composed of the film-type memory alloy and the second thin film undergoes bending deformation due to the residual compressive stress of the second thin film. When the thin-film shape memory alloy is heated, it is changed into a state to be flattened by the shape memory alloy. At this time, the liquid volume decreases, and the recording liquid is injected. During cooling, bending deformation occurs due to the residual compressive stress of the second thin film. Refilling of the liquid takes place. This process is repeated to perform continuous recording liquid injection.

The present invention has a simple structure and implements a diaphragm composed of a thin film-shaped retaining alloy and a second thin film through a semiconductor thin film manufacturing process and a substrate etching process, and records using the residual compressive stress of the second thin film produced through the semiconductor thin film manufacturing process. Since the displacement of the diaphragm required to inject the liquid can be easily implemented, the mass productivity is greatly increased, and the deformation amount can be easily adjusted by changing the magnitude of the residual stress of the second thin film, and the displacement amount can be increased, thereby reducing the area of the diaphragm. have. Therefore, the head can be miniaturized and the density of the nozzle can be increased to achieve high resolution. Further, the second thin film can realize the diversification of the structure of the recording liquid jetting apparatus by adjusting the bending deformation direction.

In the present invention, since the thin film mold suppression alloy is used, the power consumption is greatly reduced during the heating and the cooling time is also very fast, and after the injection of the recording liquid, the thin film mold suppression alloy is returned to the warpage deformation state due to the residual compressive stress of the second thin film. When the return force is strong and residual vibration does not occur, stabilized recording liquid injection can be performed. This increases the operating frequency, that is, the printing speed.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is an exploded perspective view of the jetting apparatus of an embodiment of the present invention, and FIG. 4 is a perspective view showing the recording liquid flow of the embodiment of the present invention. In the jetting apparatus of the present invention, in order to increase the resolution, a plurality of nozzles 19 in which recording liquid is injected are arranged vertically and horizontally, and the diaphragm 12 which sprays the recording liquid substantially corresponds one-to-one with these nozzles 19. . That is, a plurality of spaces 11 penetrated in the vertical direction at the front and the rear of the substrate 10 are formed, and a plurality of diaphragms 12 are coupled to the upper portion of the substrate 10 to cover each space 11. It is provided. The diaphragm 12 vibrates according to temperature, and the recording liquid 20 is injected by the generated force generated at this time. The diaphragm 12 is composed of a thin film shape memory alloy 12a and a second thin film 12b. In particular, the second thin film 12b can adjust the amount of deformation and the restoring force of the diaphragm 12. It is composed of materials and increases the operating frequency by increasing the deflection speed (restoration force).

In addition, a flow path plate 13 covering the upper portion of the substrate 10 is provided, and the flow path plate 13 is formed with a liquid chamber 14 in which the recording liquid 20 is accommodated at each upper portion of the diaphragm 12. In addition, an oil passage 15 through which the recording liquid 20 flows is provided in the center of the passage plate 13, and the oil passage 15 and the liquid chamber 14 communicate with each other through the passage 16. In addition, a liquid inlet 17 communicating with one side oil passage 15 of the flow path plate 13 is provided at one side of the substrate 10 to supply the recording liquid 20 to the oil passage 15.

In addition, a nozzle plate 18 coupled to the upper portion of the flow path plate 13 is provided, and the nozzle plate 18 is provided with a plurality of nozzles 19 corresponding to each liquid chamber 14 formed in the flow path plate 13. In addition, each nozzle 19 corresponds to the diaphragm 12 exposed toward the corresponding liquid chamber 14, and when the diaphragm 12 vibrates, the pressure of the corresponding liquid chamber 14 changes so that the recording liquid 20 is in the state of the droplet. The nozzles are sprayed onto the paper via the nozzles 19.

The thin film-shaped storage alloy 12a constituting the diaphragm 12 is continuously changed in phase with temperature change, and vibration occurs in this process, and the recording liquid 20 is sprayed in the state of droplets through each nozzle 19. . In addition, the thin film storage alloy 12a is heated by the power supply 21 as shown in FIG. 5A. That is, when the power of the power supply unit 21 is applied to the electrodes 21a coupled to both ends of the thin film storage alloy 12a, the thin film storage alloy 12a generates heat by its own resistance, thereby raising the temperature and flattening. . In addition, when the power supply to the power supply 21 is cut off, the thin film-shaped retaining alloy 12a is naturally cooled while the diaphragm 12 is restored to the original convex state by the second thin film 12b.

In addition, as shown in FIG. 5B, the heater 21b heated by the power applied from the power supply 21 may be attached to one side of the second thin film 12b to heat the thin film-shaped storage alloy 12a. In addition, as shown in FIG. 5C, in order to increase the cooling rate of the diaphragm 12, a separate heat dissipation film 12c may be attached to the bottom of the second thin film 12b. The heat dissipation film 12c is to be restored by cooling the heated diaphragm 12 in a short time, and increases the operating frequency of the diaphragm 12. The heat radiating film 12c is made of nickel (Ni) having good heat dissipation and has a thickness of about 0.5 μm to 3 μm. In addition, the thin film-type storage alloy 12a constituting the diaphragm 12 includes titanium (Ti) and nickel (Ni) as main components, and its thickness is about 0.1 µm to 5 µm. The second thin film 12a is made of thermally grown SiO ₂ , polysilicon, or the like, and has a thickness of about 0.1 μm to 3 μm.

6A to 6C are side cross-sectional views of the injector according to the embodiment of the present invention, and the material of the substrate 10 uses silicon. In the initial state in which the diaphragm 12 is deformed to block to the opposite side of the nozzle 19, when the thin film-shaped retaining alloy 12a is heated above the set temperature, the diaphragm 12 will be flattened and the internal pressure of the liquid chamber 14 will be The recording liquid 20 is ejected through the nozzle 19 while being increased and compressed.

In addition, when the thin film-shaped retaining alloy 12a falls below the set temperature, the diaphragm 12 is restored to the original convex state by the residual compressive stress of the second thin film 12b, and at this time, the internal pressure of the liquid chamber 14 is lowered. The recording liquid 20 flows into the liquid chamber 14 by the capillary phenomenon and the suction force of the nozzle 19. Thereafter, the above process is repeated continuously, and the recording liquid is sprayed in the form of droplets. In addition, when the diaphragm 12 is deformed in a blocked state, the restoring force of the diaphragm 12 is strengthened by the residual compressive stress of the second thin film 12b, thereby increasing the operating frequency. That is, the second thin film 12b can be buckleed in a short time by increasing the restoring force of the diaphragm 12. Therefore, the refilling of the recording liquid can be performed quickly so that the injection of the recording liquid can be performed immediately. The operating speed of the head is increased.

8 is a process diagram showing a method of manufacturing a diaphragm according to the present invention, and FIG. 9 is a block diagram showing a method of manufacturing a diaphragm according to the present invention, in which a semiconductor manufacturing process and a substrate etching process are used. A second thin film 12b is formed on a substrate 10 made of a material such as silicon, glass, metal, or polymer so as to have a residual compressive stress of a predetermined size by a semiconductor thin film manufacturing process. In addition, a step 101 of constructing the diaphragm 12 by depositing a thin film-shaped retaining alloy 12a on the second thin film 12b is provided. At this time, the deposition method is mainly used for the sputter deposition (Sputter-deposition), and the step (102) for the crystallization of the thin film-shaped storage alloy (12a) by a certain time heat treatment at a constant temperature to store the state of the flat plate. In step 103, the thin film-shaped storage alloy 12a is cooled to martensite by cooling the martensite termination temperature Mf to about 40 ° C to 70 ° C.

In addition, a step 105 of forming a space 11 on the substrate 10 and exposing the diaphragm 12 to the outside by etching silicon directly under the diaphragm 12 and exposing the diaphragm 12 to the outside is provided. Step 106 is provided to bend to the lower (or upper) side by the residual compressive stress of the second thin film 12b, as shown in FIG. In the process of forming the second thin film 12b by using a semiconductor manufacturing process, the amount of residual compressive stress may be adjusted according to deposition conditions and materials. Particularly, the second thin film 12b may be formed on the upper surface of the thin film storage alloy 12a or As formed downward, the bending direction of the diaphragm 12 is determined.

In the process of bending deformation as described above, the thin film-shaped storage alloy 12a maintains martensite. In addition, when the thin film-shaped retaining alloy 12a is heated to a set temperature, that is, the base end temperature Af of about 50 ° C. to 90 ° C., the recording liquid 20 is sprayed while being in the form of a flat plate as shown in FIG. 6B. do. When the thin film-shaped storage alloy 12a is cooled and becomes martensite, step 108 of replenishing the recording liquid 20 to the liquid chamber 14 while bending deformation due to the residual compressive stress of the second thin film 12b, and the thin film In accordance with the temperature change of the shape memory alloy 12a, the steps 107 and 108 above are repeated, and a step 109 is provided in which the recording liquid 20 is ejected and printed in the state of droplets.

In addition, the thin film-shaped retaining alloy 12a of the present invention becomes flat in the mother phase upon heating and warpage in martensite upon cooling, so that the frequency difference (operating frequency) of the thin film 12 increases as the temperature difference decreases. Therefore, copper (Cu) may be added to an alloy of titanium (Ti) and nickel (Ni) to reduce the temperature difference. As such, the shape memory alloy using titanium (Ti), nickel (Ni), and copper (Cu) reduces the phase change temperature difference, thereby increasing the frequency, that is, the operating frequency of the thin film-shaped storage alloy 12a, thereby increasing the printing speed.

The droplet feasibility of the thin film-type storage alloy of the present invention configured as described above is as follows.

The energy density generated by the thin film storage alloy 12a is 10 × 10 ⁶ J / m 3, and the size exposed to the space 11 of the thin film storage alloy 12a is 200 × 200 × 1 μm 3. If the diameter of the generated droplets is 60㎛, it is determined whether the thin film can be sprayed as follows.

U = energy required to generate droplets of the desired recording liquid

U _S = surface energy of recording liquid

U _K = Kinetic energy of recording liquid

R = droplet diameter

v = speed of recording liquid

ρ = density of recording liquid (1000 ㎏ / ㎥)

γ = surface tension of recording liquid (0.073 N / m)

If the desired droplet velocity is 10m / sec, the required energy (U)

U = 2.06 x 10 ^-10 +7.07 x 10 ^-10 = 9.13 x 10 ^-10

The maximum energy generated by the thin film storage alloy 12a is W _max = W _v · V

W _max = (10 × 10 ⁸ ) · (200 × 200 × 1)

= 4 x 10 ^-7 j

In addition, when the diameter of the droplet is 100 µm, the required energy U is 3.85 x 10 ^-9 j.

Therefore, since W _max 》 U, a droplet having a desired size can be realized. That is, since the thin film-type storage alloy 12a has a very high generating force, droplets of a desired recording liquid can be easily realized.

In addition, when the displacement amount according to the heating time and energy consumption and residual compressive stress of an embodiment of the present invention is as follows. The power is applied to the thin film-shaped storage alloy 12a to generate heat according to its own resistance, and the phase change is caused by the heat, but the thin film-shaped storage alloy 12a at 25 ° C. is heated to 70 ° C. The heating time and energy consumption until is as follows.

Therefore, the energy required for ejecting the recording liquid 18 to generate droplets is about 8.1 mu J, which consumes less energy than 20 mu J of the conventional heating method.

10 is a diagram showing the heating time and temperature of the thin film formation memory alloy of the present invention, and the physical properties for the experiment are as follows.

The thickness of the thin film storage alloy 12a is 1 占 퐉 and the ambient temperature is 25 占 폚.

If the ambient temperature is 25 ℃, the time to cool to 30 ℃ after changing to the heating bed to 70 ℃ is about 200μsec in terms of frequency is about 5㎑. Therefore, the operating frequency of the printhead is about 5 kHz. However, the temperature at which the deformation is completed (martensite end temperature) is about 45 ° C, so there is no need to wait until it cools to 30 ° C, and it can be heated again before continuing to spray the recording liquid 20. Can be. Larger operating frequency increases printing speed.

In addition, the displacement amount and the restoring force according to the thin film type storage alloy and its residual compressive stress are analyzed with reference to FIG.

The maximum energy generated by the thin film storage alloy is W _max = W _v · V

(W _v : energy that can be exerted per unit volume of the thin film-type storage alloy J / ㎥, V: volume of the thin film-type storage alloy)

Wmax = (10 × 10 ⁶ ) · (200 × 200 × 1) = 4 × 10 ^-7 j

Total energy (U _m ) generated by buckling of the thin-film-type storage alloy during cooling

After the injection of the recording liquid 20, the total energy generated when the thin film-shaped suppression alloy is buckled is converted into a restoring force P that causes the bending deformation of the thin film-shaped suppression alloy. Resilience is as follows.

Assuming that 1/2 of the total volume change generated by the buckling of the thin-film-shaped suppression alloy is injected, droplets of 39 mu m are formed.

The amount of displacement with respect to the thickness and size of the thin film-type storage alloy is shown in the table below, and the unit is (µm).

In addition, when there is no residual compressive stress in the thin film-shaped storage alloy 12a constituting the diaphragm 12, the displacement amount and the restoring force according to the residual compressive stress of the second thin film b are obtained as follows (see FIG. 11).

Bending energy caused by residual compressive stress of the second thin film (U _b ):

The bending energy of the second thin film is stored as the bending energy of the diaphragm 12 composed of the thin film-shaped storage alloy and the second thin film.

If the displacement amount δ of the diaphragm 12 is obtained using the above equation,

δ = 11.4 μm

The energy lost by the second thin film during the injection of the recording liquid by heating the thin film-type storage alloy is the bending energy generated by the residual compressive stress of the second thin film.

Bending energy (U _S ) = 2.9 × 10 ^-9 j

The maximum energy generated by the thin film storage alloy is W _max = W _v · V

(W _v : energy that can be exerted per unit volume of the thin film-type storage alloy J / ㎥, V: volume of the thin film-type storage alloy)

Wmax = (10 × 10 ⁶ ) · (200 × 200 × 1)

= 4 x 10 ^-7 j

The energy ratio U _S / W _max consumed by the second thin film with respect to the maximum energy that the thin film type alloy can produce is 0.73%. Therefore, the effect of energy loss by the second thin film upon discharging the recording liquid can be ignored.

Total energy (U _S ) generated when the second thin film is left buckled

The total energy U _S generated when the second thin film is buckled after recording liquid injection is changed into the restoring force P of the diaphragm 12. Resilience is as follows.

Assuming that half of the total volume change due to the deformation of the diaphragm 12 is injected, the droplet diameter is 51 mu m.

Comparing the diaphragm composed of the thin film type suppression alloy and the diaphragm composed of the thin film type suppression alloy and the second thin film, the displacement amount increased about 2 times from 6.2 μm to 11.4 μm and the restoring force increased about 20 times from 4.5 KPa to 107.1 KPa. . Therefore, using the second thin film can easily obtain the required displacement amount and increase the restoring force.

The displacement amount of the diaphragm 12 composed of the thin film-type storage alloy and the second thin film is as follows, and the unit is (µm).

12 is a cross-sectional view of an injector according to another embodiment of the present invention, in which the same components as in FIG. 3 will be described with the same reference numerals. According to another embodiment of the present invention, the flow path plate 13 and the nozzle plate 18 are provided below the substrate 10, and an extraction state of any one thin film is extracted. The space part 11 penetrated in the up-and-down direction is formed in the board | substrate 10, and the diaphragm 12 which is coupled to the upper part of the board | substrate 10 and covers the space part 11 is provided. The diaphragm 12 vibrates according to the temperature change of the thin film-shaped storage alloy 12a, and the recording liquid 20 is injected by the generated force generated at this time. In addition, the second thin film 12b constituting the diaphragm 12 increases the bending strain rate (restoration force) of the diaphragm 12 to increase the operating frequency.

In addition, a flow path plate 13 covering the lower portion of the substrate 10 is provided, and the flow path plate 13 is formed with a liquid chamber 14 corresponding to the space 11 so as to accommodate the recording liquid 20. In addition, a nozzle plate 18 coupled to the lower portion of the flow path plate 13 is provided, and the nozzle plate 18 is formed with a nozzle 19 corresponding to the liquid chamber 14 formed in the flow path plate 13. In addition, the nozzle 19 corresponds to the diaphragm 12 exposed toward the liquid chamber 14, and when the diaphragm 12 is deformed, the pressure of the liquid chamber 14 changes, so that the recording liquid 20 is in the state of droplets. It is sprayed on the paper through).

According to another exemplary embodiment of the present invention configured as described above, after the thin film-type storage alloy 12a is formed on the substrate 10, the second thin film 12b is deposited on the thin-film storage alloy 12a. Then, when the space 11 is formed in the lower portion of the substrate 10 by etching, the diaphragm 12 is deflected by the residual compressive stress of the second thin film 12b. When the thin film-shaped retaining alloy 12a is heated in the warped state as described above, the diaphragm 12 is deformed into a state of a flat plate, and then, when cooled, the warp strained to an initial state. In addition, since the restoring force is strengthened by the residual compressive stress of the second thin film 12b during the bending deformation of the diaphragm 12, the operating frequency is increased.

13 is a cross-sectional view of the injector of another embodiment of the present invention, in which the same components as in the embodiment of the present invention will be described using the same reference numerals. In another embodiment of the present invention, the diaphragm 12 is formed under the substrate 10, and the flow path plate 13 and the nozzle plate 18 are formed on the substrate 10, respectively. That is, the diaphragm 12 protrudes into the space part 11 in the initial state in which the thin film-shaped retaining alloy 12a is not heated and becomes flat when heated. Accordingly, the recording liquid 20 is flattened when the diaphragm 12 is heated, and the recording liquid 20 is supplemented into the liquid chamber 14 and is deflected when cooled, thereby increasing the pressure in the liquid chamber 14 to eject the recording liquid 20. .

14 is a cross-sectional view of the injector of another embodiment of the present invention, in which the same components as in the embodiment of the present invention will be described with the same reference numerals. Another embodiment of the present invention uses a plurality of second thin films 12b, and the second thin films may be formed of different materials. a is two second thin films 12b formed on the bottom of the thin film storage alloy 12a, and b is a second thin film 12b formed on the upper and lower portions of the thin film storage alloy 12a, respectively. This configuration can further reinforce the restoring force of the diaphragm 12 and more easily implement the required displacement amount. In addition, reliability is secured by increasing the durability of the diaphragm 12.

As described above, according to the present invention, the recording liquid is injected by the vibration of the diaphragm as the temperature of the thin film-type storage alloy is changed. In addition, when the second thin film having residual compressive stress is combined and restored to an initial state (bending deformation state) upon cooling, the restoring force is enhanced by the residual compressive stress, thereby increasing the operating frequency. In addition, since the diaphragm has a large displacement amount, each space part formed in the substrate and each liquid chamber formed in the flow path plate can be made small, so that the overall size of the print head can be reduced and made small, which is advantageous for achieving high resolution by increasing the concentration of nozzles.

In addition, the strength of the diaphragm is increased by the second thin film, so there is little fear of damage due to external impact. In addition, since the generating force is large, the pushing force of the recording liquid is increased to reduce the clogging of the nozzle, thereby improving reliability, and the droplet size of the recording liquid can be sufficiently reduced, which is advantageous for achieving high image quality. In addition, since the driving voltage is less than 10 volts, it is easy to design and manufacture the driving circuit, and the diaphragm can be easily implemented using the existing semiconductor process and the etching process, thereby improving mass productivity and simplifying the structure.

Claims (19)

Vibration having at least one second thin film 12b of the shape memory alloy material which is changed in shape with temperature change and coupled to the thin film shape memory alloy 12a and at least one second thin film 12b for controlling the shape change amount thereof. A pipe 12, a power supply 21 for generating a temperature change of the thin film storage alloy 12a, and a liquid chamber 14 installed on the thin film storage alloy 12a to store the recording liquid 20 And a flow path plate 13 having a flow path 16 formed thereon so that the recording liquid 20 flows into one side of the wall surface surrounding the liquid chamber 14, and is installed on the flow path plate 13. Nozzle plate 18 having a nozzle 19 having an area smaller than the area of the liquid chamber 14 of the flow path plate 13 so that the recording liquid 20 can be ejected in the form of droplets when the shape of the shape 12 changes. Recording liquid injection device of the printhead having a. The apparatus of claim 1, wherein the thin film-shaped storage alloy (12a) is a shape memory alloy composed mainly of titanium (Ti) and nickel (Ni). The apparatus of claim 1, wherein the thin film-shaped storage alloy (12a) is a shape memory alloy to which copper (Cu) is further added to reduce the phase change temperature difference to increase the operating frequency. The recording liquid jetting apparatus according to claim 1, wherein the thin film-shaped storage alloy (12a) has a thickness of about 0.3 µm to 5 µm. The recording liquid jetting apparatus according to claim 1, wherein the thickness of the second thin film (12b) is about 0.1 mu m to 3 mu m. The recording liquid jetting apparatus according to claim 1, wherein the second thin film (12b) includes thermal silicon oxide (SiO ₂ ). The recording liquid jetting apparatus according to claim 1, wherein the second thin film (12b) comprises polysilicon. The method of claim 1, wherein the power supply unit 21 is characterized in that it comprises an electrode (21a) coupled to both ends of the thin-film-type storage alloy (12a) so that the thin-film-type storage alloy (12a) is generated by its own resistance The recording liquid jetting apparatus of the printhead. The method of claim 1, wherein the power supply unit 21 is characterized in that it comprises a heater (21b) for heating the thin-film-type storage alloy (12a) by the power applied to the formed on one side of the diaphragm 12 The recording liquid jetting device of the printhead. The printing apparatus according to claim 1, further comprising a heat dissipation film (12c) formed on one side of the diaphragm (12) to dissipate heat when the thin-film-shaped storage alloy (12a) is heated and cooled. Head of recording liquid injector. 11. The recording liquid jetting apparatus according to claim 10, wherein the heat radiation film (12c) has a thickness of about 0.5 mu m to 3 mu m. 11. The recording liquid jetting apparatus according to claim 10, wherein the heat dissipation film (12c) includes nickel (Ni) having good thermal conductivity. The recording liquid jet of the printhead according to claim 1, further comprising a substrate (10) provided under the diaphragm (12) and having a space (11) formed therein so that the diaphragm (12) can change shape. Device. The area (b) of claim 13, wherein the diaphragm (12) is exposed to the space portion (11) to substantially change its shape, and the width (b) is 100 µm to 500 µm, and the length (a) is 100 µm to The recording liquid jetting apparatus of the printhead, characterized in that 300㎛. 15. The recording liquid jetting apparatus according to claim 13, wherein the substrate (10) is made of a single crystal silicon material. The method of claim 1, wherein the diaphragm 12 is heated to the end phase of the thin film-shaped retaining alloy 12a to form a flat plate, and is cooled to the end temperature of martensite to form martensite. A printing liquid jetting apparatus for a print head, characterized by bending deformation caused by residual compressive stress of the two thin films (12b). 17. The recording liquid jetting apparatus according to claim 16, wherein a mother phase end temperature of the thin film-type storage alloy 12a is about 50 ° C to 90 ° C, and the martensite end temperature is about 40 ° C to 70 ° C. . 17. The recording liquid jetting apparatus according to claim 16, wherein the thin film-shaped retaining alloy (12a) is heated to a mother phase and cooled to martensite of about 200 µsec or less and an operating frequency of 5 Hz or more. . Forming a second thin film 12b on the substrate 10 so as to have a residual compressive stress, and forming a diaphragm 12 by depositing a thin film-type retaining alloy 12a on the second thin film 12b. Step (101), heat treating the thin film-shaped storage alloy (12a) to store a flat plate as a matrix, and cooling the thin film-shaped storage alloy (12a) to form martensite (103). ) And etching a portion of the substrate 10 so that a portion of the diaphragm 12 is exposed 104, and an exposed portion of the diaphragm 12 is a residual compressive stress of the second thin film 12b. The step 105 of bending deformation by the step, the step 106 of spraying the recording liquid 20 while the thin film-shaped storage alloy 12a is heated to form a flat plate, and the thin film-shaped storage alloy 12a When it cools and becomes martensite, it deflects by the residual compressive stress of the second thin film 12b and the liquid into the liquid chamber 14. The recording liquid 20 is replenished in step 107 and the above-mentioned steps 106 and 107 are repeated according to the temperature change of the thin film-shaped storage alloy 12a. A recording liquid jetting method of a printhead, comprising the steps of: (108) ejected and printed in an enemy state.

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