JP2000177128A - Liquid ejector and liquid ejecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid ejector in which efficiency of energy utilization is enhanced, an actuator can be driven with large displacement and pressure variation rate is increased in pressurization chamber. SOLUTION: A liquid ejector comprises a liquid pressurization chamber 109, a liquid ejection opening 110 provided at a part of the liquid pressurization chamber 109, a liquid pressurizing member 103 disposed contiguously to the liquid pressurization chamber 109, and a liquid channel 108 made contiguously to the liquid pressurization chamber 109 wherein a liquid is ejected from the liquid ejection opening 110 by driving the liquid pressurizing member 103 to pressurize a liquid supplied to the liquid pressurization chamber 109. Cross-sectional area of the liquid pressurization chamber 109 normal to the displacement direction of the liquid pressurizing member is smaller than the area of the liquid pressurizing member 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid ejecting apparatus used for a printer or the like.

[0002]

2. Description of the Related Art In recent years, ink-jet printers have rapidly spread as printers capable of realizing color printing at low cost. It is the ink ejecting device that determines the performance of the ink jet printer, and the liquid ejecting device that intermittently ejects fine liquid particles.

Here, as a conventional liquid ejecting apparatus, an ink ejecting apparatus for a typical ink jet printer will be described as an example. Ink jet devices for inkjet printers can be broadly classified into two types: thermal type and piezoelectric type.

A typical principle of thermal injection will be described with reference to FIG. FIG. 16 is a cross-sectional view of an ink ejecting element constituting the ink ejecting apparatus. An ink pressurizing chamber 803 is provided in a gap between the substrate 801 and the substrate 802, and a heater 804 is provided in the ink pressurizing chamber 803. The ink is supplied from an ink storage unit (not shown) provided outside the ink ejection element by a capillary action or an external suction operation, and is supplied to an ink pressurizing chamber 803 through an ink flow path 806. In this state,
When an electric current is applied to the heater 804, the ink bumps and bubbles are generated. Due to the growth of the bubbles, the ink pressurizing chamber 80
The pressure in the nozzle 3 is increased, and ink is ejected from the ink ejection port 805. An actual ink ejecting apparatus has a structure in which a plurality of the above-described ink ejecting elements are connected.

Next, an example of a typical ink jet device for a piezoelectric type ink jet printer will be described with reference to FIG. 17, which is a sectional view of an ink jet element. 81 in FIG.
Reference numeral 3 denotes a piezoelectric actuator driven by a piezoelectric action, such as a bimorph element composed of two piezoelectric bodies or a unimorph element composed of a piezoelectric body and a diaphragm. Reference numeral 818 denotes an ink flow path, 819 denotes an ink pressurizing chamber, and 820 denotes an ink ejection port. The broken line of the piezoelectric actuator 813 indicates the piezoelectric actuator 81.
3 is a schematic representation of a modification of FIG.

[0006] Initially, ink is supplied from an ink storage unit (not shown) provided outside the ink ejecting element by a capillary action or an external suction operation, and an ink flow path 818 is provided.
Is supplied to the ink pressurizing chamber 819. When the piezoelectric actuator 813 is deformed as indicated by a broken line in a state where the ink flow path 818 and the ink pressurizing chamber 819 are filled with ink, the pressure in the ink pressurizing chamber 819 increases, and ink is ejected from the ink ejection port 820. Is done. An actual ink ejecting apparatus has a structure in which a plurality of the elements described above are arranged in a line for high-speed printing.

In recent years, there has been an increasing demand for an inexpensive ink jet printer capable of expressing high-definition colors, and in order to perform color printing with an ink jet printer using the above-described liquid ejecting device more vividly. Is
It has become necessary to increase the number of gradations per unit pixel (pixel), that is, to realize multi-gradation printing.

A method for realizing such multi-tone printing will be described below.

First, there is a method based on an area modulation method. In this method, a plurality of dots are struck without overlapping to form a unit pixel (pixel) for expressing light and shade, and gradation is expressed by changing the ratio of ink per unit pixel.

Second, there is a method of overprinting dots. This method is a method in which ink is ejected to the same place a plurality of times and the size of a unit pixel is changed to perform gradation expression.

Third, there is a method based on a density modulation method. This method is a method of expressing gradation using a plurality of inks having different dye concentrations.

Fourth, there is a method using a dot modulation method. In this method, ink droplets of different sizes are ejected from the same ejection port, and the dot size can be changed by one ejection.

[0013]

However, the methods for realizing the multi-tone printing have the following problems.

First, with respect to the problem of the area modulation method, since the density is expressed by thinning out the dots to be recorded, the unit pixel size required for expressing the density becomes large, and the substantial recording density is reduced. Will be lowered. Therefore, when trying to express multiple shades of light and shade, the printing becomes conspicuous in the low density portion. In order to reduce the decrease in the recording density, it is necessary to reduce the size of the unit pixel as much as possible, that is, to reduce the minimum dot diameter. In order to discharge a small ink droplet in order to reduce the minimum dot diameter, it is necessary to reduce the ejection port diameter or to devise a discharge method. However, the ejection diameter of the conventional ink jet head has been reduced to about 20 to 30 microns, and opening an ejection port of a smaller diameter requires a more difficult manufacturing process, and furthermore, providing a larger number of ejection ports. Inevitably, which leads to an increase in manufacturing costs. In addition, the small-diameter ejection port causes a drop in product reliability such as ink clogging and ejection failure due to dust mixed into the ink. Further, even if the above-mentioned problem is solved and an ink droplet having a small dot diameter can be ejected, a problem that the printing speed is reduced occurs. This is a problem that occurs because more ink droplets must be ejected in order to fill the same area, and to solve this problem, the ejection repetition time is shortened (for an ink ejection device). High-speed drive), number of elements (number of injection ports)
It is necessary to take measures such as increasing The former is difficult in the case of a thermal type ink ejecting device due to the rate control of the heat transfer time.
In the case of the piezoelectric type ink ejecting apparatus, there is a possibility that high-speed driving can be performed as compared with the thermal type, but there is a limit due to the ability of the liquid to follow the piezoelectric actuator. In addition, the latter causes problems such as an increase in the complexity of the device and a decrease in manufacturing yield, resulting in an increase in cost.

Second, there is a problem with the method of dot overprinting, which is similar to the problem in the area modulation method because a large number of dots smaller than the unit pixel must be formed within the unit pixel. Issues arise.
In addition, since the liquid lands in the same location intensively,
The graining phenomenon easily occurs, and the printing tends to be rough.

Third, with respect to the problem of the density modulation system, it is necessary to equip a plurality of inks with different dye densities, causing problems such as an increase in complexity and size of the apparatus and an increase in cost. I do. Further, as the number of types of ink increases, the number of elements that can be used substantially decreases (number of elements / type of ink), and a problem such as a decrease in printing speed occurs.

Fourth, with respect to the problem of the dot modulation system, the dot diameter is modulated by directly changing the ejection amount to be ejected at a time, so that the problems of the above three types of modulation systems are greatly reduced. You. For example, since a unit pixel is composed of one dot, it is possible to perform shading expression without increasing the unit pixel size. Further, since it is not necessary to form a large number of dots on a unit pixel, it is not necessary to increase the number of ejection ports, and printing can be performed at high speed.

As described above, the fourth dot modulation method is the most excellent among the conventional methods for realizing multi-tone printing. However, in the conventional ink ejecting apparatus, it is very difficult to realize the dot modulation method itself, that is, to perform dot modulation itself by ejecting droplets having different diameters from the same liquid ejecting apparatus.

In a conventional thermal ink jet apparatus, since the ink is jetted using the bumping phenomenon, it is extremely difficult to control the ink jet printer. Control. Therefore, in general, shading is expressed by an area modulation method, a density modulation method, or a combination of the two, and there is a problem as described above.

In the conventional piezoelectric type, unlike the thermal type, it is possible to control the amount of ejected ink to some extent by controlling the amount of displacement of the piezoelectric actuator. However, at present, the number of gradations is about 2 to 6 and the modulation width is about 2 which is insufficient. However, the modulation width is defined as the ratio between the minimum ink ejection amount (volume) and the maximum ink ejection amount (volume). Originally, it should be defined by the ratio of the recorded dot diameters. However, since the dot diameter greatly changes depending on the physical properties of ink and paper, it is defined as described above. Therefore, even in the conventional piezoelectric method, in order to perform the gradation expression, the area modulation method, the density modulation method, or a combination of the two methods is used to perform the gradation expression, and thus the above-described problem occurs.

The conditions for realizing dot modulation in the piezoelectric liquid ejecting apparatus and the current problems will be described in more detail.

In order to realize dot modulation, first, it is necessary to increase the width of the amount of energy that can be supplied to the liquid to be ejected. This is a condition required to increase the modulation width because the required energy amount varies depending on the amount of droplets to be ejected. Normally, the rate is limited by the upper limit, but the amount of energy that can be supplied to the device is limited, so that it is necessary to increase the energy use efficiency of the device. Secondly, in order to eject large droplets, it is necessary to adopt a configuration in which the amount of displacement of the piezoelectric actuator can be made large (large displacement characteristics). In the ejection of a relatively large droplet, the larger the displacement of the piezoelectric actuator, the larger the droplet diameter. That is, the droplet diameter can be modulated using the displacement amount as a parameter. Third, in order to eject small droplets, it is necessary to change the pressure of the liquid pressurizing chamber from low pressure to high pressure in a very short time while reducing the displacement of the piezoelectric actuator (pressure response characteristic). In this case, droplet modulation can be performed using the speed of pressure change in the liquid pressurization chamber as a parameter. Fourth, it is necessary to accurately control the displacement amount of the piezoelectric actuator and the speed of the pressure change in the liquid pressurization chamber (controllability).

It is difficult for the conventional piezoelectric liquid ejecting apparatus to satisfy the above conditions.

Further description will be made with reference to FIG. When the piezoelectric actuator 813 is displaced downward (in a broken line), the pressure in the ink pressurizing chamber 819 increases. Accordingly, the piezoelectric actuator 813 is moved to the ink pressurizing chamber 819.
Therefore, the displacement amount of the piezoelectric actuator 813 is extremely small as compared with the displacement amount when there is no load such as ink.

When the piezoelectric actuator 813 is displaced downward (in a broken line), the pressure in the ink pressurizing chamber 819 increases, but at the same time, the pressure in the ink flow path 818 also increases. Here, less than half of the work that has acted on the ink due to the displacement of the piezoelectric actuator 813, that is, the work that has been supplied to the ink, is used to increase the pressure of the ink pressurizing chamber 819. The remaining energy is consumed by the pressure rise and loss of the ink flow path 818. This is because the ink flow path 815 and the ink pressurizing chamber 818
Though some improvement can be achieved by devising the shape near the boundary of (e.g., attaching a check valve), it does not solve the fundamental problem, and the energy use efficiency is 10-20% at most.
It is only raised about. In addition, the piezoelectric actuator 811 is generally fixed to the ink pressurizing chamber 818 on all four sides in order to maintain airtightness in the ink pressurizing chamber, so that the displacement amount is small in principle. Further, in order to compensate for the small displacement amount and increase the ink ejection amount, it is necessary to increase the cross-sectional area of the ink pressurizing chamber 818 whose normal direction is the displacement direction. Problems such as an increase in indoor energy loss and an increase in the above-described reaction force also occur. For the reasons described above, in the current piezoelectric liquid ejecting apparatus, the number of gradations is 2 to 2.
6, the modulation width is about 8.

As a method of increasing the modulation width while keeping the energy utilization efficiency as it is, it is conceivable to increase the variable width of the amplitude value of the applied voltage, that is, increase the maximum applied voltage value. This causes the following problems. First, current piezoelectric actuators do not have a sufficient withstand voltage, so that the life of the element is shortened or the element is destroyed. In addition, when the element is damaged, the piezoelectric actuator is normally in an electrically short-circuited state, which causes a problem in safety. Second, the piezoelectric body is often polarized in the driving voltage application direction,
By applying a high voltage, part or all of the polarization is lost, and the characteristics are degraded. In extreme cases, the piezoelectric characteristics themselves are lost. Further, the disappearance of the polarization leads to a deterioration of the life of the element. Third, when considering home use, raising the applied voltage itself poses problems in safety and economy. Fourth, peripheral circuit elements become complicated and large, resulting in an increase in cost. Due to the above problems, it is not practically preferable to increase the applied voltage.

The liquid ejecting apparatus and the ejecting method according to the present invention solve the above-mentioned problems, and have a structure for improving the energy use efficiency of the liquid ejecting apparatus.
The actuator can be driven to a large displacement.
It is an object of the present invention to provide an invention having a configuration for increasing the rate of change of pressure in a pressurized chamber.

Another object of the present invention is to provide a method for manufacturing a liquid ejecting apparatus having a wide modulation width at a low cost and easily. .

[0029]

According to the present invention, at least a liquid pressurizing chamber, a liquid ejection port provided in a part of the liquid pressurizing chamber, and a liquid pressurizing chamber are disposed adjacent to the liquid pressurizing chamber. A liquid pressurizing member, and a liquid flow path disposed adjacent to the liquid pressurizing chamber are provided, and the liquid pressurizing member is driven to supply the liquid from the liquid flow path to the liquid pressurizing chamber. By pressurizing the liquid, in the liquid ejecting apparatus that ejects the liquid from the liquid ejecting port, an area in a cross section of the liquid pressurizing chamber having a displacement direction of the liquid pressurizing member as a normal direction,
The liquid ejecting apparatus is characterized in that the area is smaller than the area of the liquid pressurizing member.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIG. 1 and FIG. FIG. 1A is a cross-sectional view of one element of the liquid ejecting apparatus according to the present embodiment.
(B) is a top view illustrating a part of the liquid ejecting apparatus according to the present embodiment. In the figure, two liquid ejecting elements of the liquid ejecting apparatus are shown. FIG. 2 is a perspective view of the liquid ejecting apparatus. An actual liquid ejecting apparatus has a form in which a plurality of liquid ejecting elements are connected. 1 and 2, reference numeral 101 denotes a piezoelectric ceramic substrate. 102 is a diaphragm, for example,
This is a diaphragm made of stainless steel. 103 is a piezoelectric substrate 101
And a unimorph type piezoelectric actuator composed of the vibration plate 102. However, although not shown in the figure, on the piezoelectric ceramic substrate 101, excitation electrodes are provided over substantially the entire surface of the piezoelectric ceramic substrate 101. 105 is a liquid flow path 108 and the liquid pressurizing chamber 1
09 is a liquid chamber forming substrate mainly formed of, for example, a stainless steel substrate. 106 is an injection port 110
Is, for example, a nickel substrate formed by electroforming. A holding substrate 107 for holding the actuator 103 is, for example, a stainless steel substrate. 10
Reference numeral 8 denotes a liquid flow path, as described above, which is usually partially or entirely filled with liquid. Further, the liquid flow paths 108 are disposed on the left and right of the liquid pressurizing chamber 109. 1
Reference numeral 09 denotes a liquid pressurizing chamber, as described above, which is usually mostly filled with liquid. 110 is a liquid ejection port.

Reference numeral 112 denotes a partition part of the liquid pressurizing chamber,
Reference numeral 13 denotes a low-rigidity layer, which is a resin layer having a lower rigidity than the liquid flow path 108 and the piezoelectric actuator 103, for example. 114
Denotes a polishing stopper substrate, for example, a substrate made of stainless steel. Reference numeral 115 denotes a liquid supply port for supplying a liquid from the liquid flow path 108 to the liquid pressurizing chamber 109.

Next, the structure and dimensions of the liquid ejecting apparatus according to the present embodiment will be described. Piezoelectric substrate 101
The diaphragm 102 is bonded with an adhesive. The piezoelectric substrate 101 has a thickness of 45 μm, a length of 2.5 mm, and a width of 200 μm.
μm. The actuator section of the vibration plate 102 has a thickness of 105 μm, and has the same length and width as the piezoelectric substrate 101. The distance between adjacent liquid ejecting elements is the same as in the first embodiment. In addition to being supported by the holding substrate 107 at both ends, the piezoelectric actuator 103 is also supported on the upper surface of the liquid pressure chamber partition wall portion 112 via the low-rigidity layer 113.

The low-rigid layer 113 is a resin layer having a thickness of 30 μm, and its elastic modulus is 1/10 that of the material forming the piezoelectric actuator 103 or the liquid chamber forming substrate 105.
It is as follows. Normally, the elastic modulus of the low-rigid layer 113 is 1/5 of the rigidity of the piezoelectric actuator 103 with respect to the load in the direction of displacement to the position where the low-rigid layer 113 is provided.
It takes the following values, but preferably a value of 1/10 or less. The liquid channel 108 has a length of 2.5 mm and a depth of 200 mm.
μm. The inner dimensions of the liquid pressurizing chamber 109 are 140 μmφ in cross section and 400 μm in depth. From the upper surface of the liquid pressurizing chamber partition portion 112, the outer diameter is 200 μmφ.
And the inner diameter is 140 μmφ. Injection port forming substrate 10
6 has a thickness of 30 μm, and the opening diameter of the injection port 110 is 30 μm.
It is. The liquid chamber forming substrate 105 and the ejection port forming substrate 106 are adhered by an adhesive. The dimensions described above are merely examples, and the present embodiment is not limited to these dimensions. Embodiment 2
7 is the same.

The liquid ejecting apparatus according to the present embodiment is not explicitly shown in the drawing because the drawing is complicated, but the electrode on the upper surface of each liquid ejecting element is previously provided on the holding substrate 107 by wire bonding. Drawn out to the electrode drawing pad. The same applies to other embodiments described below.

Next, a method of manufacturing the liquid ejecting apparatus according to the present embodiment will be described with reference to FIGS. First, a method of manufacturing each substrate will be described in order with reference to FIGS. 3A to 3F which are top views of each substrate. The stainless substrate is machined into a shape as shown in the figure by mechanical cutting to obtain a holding substrate 107 (FIG. 3).
(A)). Next, the outer shape of the piezoelectric ceramic substrate having a thickness of 200 μm is cut by a dicing saw to obtain a piezoelectric substrate 101 (FIG. 3B). Next, the stainless steel substrate is hollowed out by etching to form the diaphragm 102 (FIG. 3).
(C)). The stainless steel substrate is hollowed out by etching to obtain a stainless steel substrate 114 to be used as a polishing stopper (FIG. 3D). However, the polishing stopper substrate 114 has the same thickness as the finally desired thickness of the piezoelectric substrate 101. For example, in the present embodiment, since the final thickness of the piezoelectric substrate 101 is 30 μm, the thickness of the polishing stopper substrate 114 is 30 μm in advance. A liquid passage 108 is formed by half-etching the stainless steel substrate, and a liquid pressurizing chamber 109 is formed by laser processing to obtain a liquid chamber forming substrate 105 (FIG. 3).
(E)). Further, a resin having low rigidity is applied to the partition 112 of the liquid pressurizing chamber, and the liquid supply port 115 is formed by laser processing.
Is provided. The injection port forming substrate 106 is formed by electroforming (FIG. 3F).

Next, a method of manufacturing the piezoelectric actuator 103 will be described with reference to FIG. In FIG. 4, (a),
(B) and (e) are top views, and (c) and (d) are cross-sectional views of (a) and (b), respectively. First, the piezoelectric substrate 10
1. The vibration plate 102 and the polishing stopper substrate 114 are fixed by an adhesive as shown in FIGS. 4 (a) and 4 (c). FIG.
In (c), the distance between the piezoelectric substrate 101 and the polishing stopper substrate 114 is about 25 μm. Next, the piezoelectric substrate 10
1 is polished to a thickness of 45 μm (FIGS. 4B and 4D).
At this time, since the thickness of the polishing stopper substrate 114 was previously 45 μm, the thickness of the piezoelectric substrate 101 was 45 μm.
At the time when the thickness becomes μm, the piezoelectric substrate 101 is hardly polished. This is because the polishing speed of the polishing stopper substrate 114 made of stainless steel is sufficiently lower than the polishing speed of the piezoelectric substrate 101.
Reference numeral 14 serves to stop polishing of the piezoelectric substrate 101. Next, a step of removing a portion of the piezoelectric substrate 101 that does not overlap with the vibration plate 102 is performed. Fig. 4
(D) Fine abrasive grains are sprayed from below to process only the piezoelectric substrate 101 into the shape shown in FIG. This method is generally called a sand blast, and the vibration plate 102 plays a role of a mask when processing the piezoelectric substrate 101. This processing method also utilizes the fact that the processing speed of the diaphragm 102 is lower than that of the piezoelectric substrate 101.

Finally, the liquid ejecting apparatus of the present embodiment is completed by bonding and assembling the substrates.

Next, the injection method of the liquid injection device according to the present embodiment will be described. First, the operation principle of the piezoelectric actuator 103 will be described. 5A to 5C show the operation of the piezoelectric substrate alone, and FIGS.
(F) is a diagram showing the operation of the piezoelectric actuator 503. Basically, the operating principles of the piezoelectric actuator 103 and the piezoelectric actuator 503 are the same. 5 in FIG.
01 is a piezoelectric substrate, 520a is an upper electrode provided on the piezoelectric substrate, and 520b is a lower electrode. A diaphragm 502 is a conductor such as a metal, for example. Reference numeral 503 denotes a unimorph type piezoelectric actuator. First, the operation of the piezoelectric substrate 501 will be described. A pulse electric field is applied to the piezoelectric substrate 501 in the thickness direction, that is, the upper surface electrode 520a
When a voltage is applied between the lower electrode 520b and the lower electrode 520b, it has the property of expanding and contracting in the length direction (lateral direction). For example, when a negative electric field is applied, the piezoelectric substrate 501 contracts as shown in FIG. 5B, and when a positive electric field is applied, the piezoelectric substrate 501 expands as shown in FIG. 5C. By alternately applying a positive and a negative electric field to the piezoelectric substrate having such characteristics, the expansion and contraction operation of the piezoelectric substrate can be obtained. Such a mode of operation is called a length vibration mode. Next, the piezoelectric actuator 503 will be described. FIG.
When a pulse voltage is applied to the upper surface electrode 520a and the diaphragm 502 in (d), when a negative electric field is applied, the piezoelectric substrate 501 tries to shrink, but the diaphragm 502 tries to hold the state, and as a result, As shown in FIG. 5E, the piezoelectric actuator 503 is bent in a downwardly convex shape. Conversely, when a positive electric field is applied, the piezoelectric substrate 501 tries to expand, but the diaphragm 502 tries to maintain the state, and as a result, as shown in FIG. Actuator 503 flexes. As described above, the piezoelectric actuator 5 is formed by alternately applying the plus and minus electric fields.
03 bending operation can be obtained. Such a mode of operation is called a bending vibration mode. In the above description, the diaphragm 502 is a conductor, but a substrate such as an insulator or a semiconductor may be used as the diaphragm. In this case, for example,
The structure is as shown in FIG. In FIG. 5G, a lower surface electrode 520b is provided below the piezoelectric substrate 501, and the vibration plate 51 is provided.
It is bonded to 2. The operation is the same as that of the bending vibration mode described above.

Next, the liquid ejecting method will be described with reference to FIG. FIG. 6A is an enlarged view of a cross section near the liquid pressurizing chamber 109 of the liquid ejecting element in a state where no voltage is applied. FIG. 6B is an enlarged cross-sectional view of the vicinity of the liquid pressurizing chamber 109 of the liquid ejecting element when a voltage is applied, the piezoelectric actuator 103 is displaced, and liquid is ejected from the liquid ejecting port 110. The liquid supplied from the liquid tank (not shown in the drawing) of the liquid ejecting device to the liquid flow path 108 of each element passes through the liquid supply port 115 due to capillary action or a pressure difference between the chambers. Pressurizing chamber 10
9 (FIG. 6A). The pressure difference is generated by operating the piezoelectric actuator 103 or sucking the liquid from the liquid ejection port 110.
When the piezoelectric actuator 103 is bent downward, the low-rigidity layer 113 is contracted and deformed, and the liquid pressurizing chamber 109 is deformed.
The internal pressure increases, and liquid is ejected from the liquid ejection port 110. Further details will be described. Piezoelectric actuator 10
When 3 is bent downward, the volume of the liquid pressurizing chamber 109 decreases. Here, the liquid supply port 105 is small, and the pressure leakage to the liquid flow path 108 is small, that is, the liquid flows out to the liquid pressurizing chamber 109 is small, and
A pressure rise occurs in the liquid pressurizing chamber 109 because the liquid ejection port 110 is small. As a result, the liquid is ejected from the liquid ejection port 110. In contrast, the liquid flow path 108 is not sealed, so there is no pressure increase.
After the ejection, the pressure in the liquid pressurizing chamber 109 decreases, the piezoelectric actuator 103 is displaced upward, and the liquid is supplied again from the liquid flow path 108 through the liquid supply port 115. The main factor of the liquid supply is the liquid flow path 10 described above.
8 and the pressure difference between the liquid pressurizing chambers 109. Of course, there is also an effect due to the capillary phenomenon.

When the above-described liquid ejecting apparatus according to the present embodiment is used, the number of controllable gradations is 4 to 8, which is larger than that of the conventional piezoelectric type.

Next, the features and effects of the liquid ejecting apparatus according to the present embodiment will be described. A feature of the liquid ejecting apparatus according to the present embodiment is that, first, the area of the piezoelectric actuator 103 is the cross-sectional area of the liquid pressurizing chamber 109 (FIG. 1).
(Area of the liquid pressurizing chamber 109 in (b)).
Is concentrated in the liquid pressurizing chamber 109. The second feature is realized by the following two items. The first matter is that the piezoelectric actuator 103 and the liquid pressurizing chamber partition portion 112
The piezoelectric actuator 103 is held at both ends by a highly rigid holding substrate 107 and a liquid chamber forming substrate 10.
5 is held. As a result, the piezoelectric actuator 10 immediately above the liquid pressurizing chamber 109
3, the displacement amount of the liquid pressurizing chamber 109 can be increased.
This will promote the concentration of the pressing force. Second, as described above, since there is no pressure increase in the liquid flow path 108, the reaction force received by the piezoelectric actuator 103 from the liquid in the liquid flow path 108 is reduced, and the pressure applied to the liquid pressurizing chamber 109 is concentrated. Will be encouraged. These features have the following effects. By generating a high pressure only in the pressurized chamber having a smaller cross-sectional area than the area of the displacement portion of the actuator, energy generated by the actuator can be concentrated in the pressurized chamber, and the energy efficiency can be increased. Therefore, even with the same input power, the range of modulation is wider than that of a conventional piezoelectric liquid ejecting apparatus,
The number of gradations is also improved. In addition, by using the liquid ejecting apparatus of the present embodiment and the ejecting method thereof, it is possible to further increase the pressure difference between the liquid flow path 108 and the liquid pressurizing chamber 109 after the ejection, and to reduce the effect due to the capillary phenomenon. For example, the liquid supply capacity to the liquid pressurizing chamber 109 after ejection is increased, and the supply of the liquid can sufficiently catch up even when the piezoelectric actuator 103 is driven at a high speed, thereby enabling high-speed printing. Even when air bubbles are mixed, there is an effect that defoaming becomes possible while performing liquid ejection. Note that, even when the liquid ejecting apparatus according to the present embodiment is not used for multi-tone printing, there is also an effect that the power consumption of the liquid ejecting apparatus can be reduced due to its high energy use efficiency. The liquid pressurizing chamber 1 is formed in the liquid flow path 108 by the action of surface tension and pressure difference.
As long as the liquid is supplied to 09, it is sufficient. In the second embodiment, a low-rigidity element 1 having a cylindrical shape is used.
13 is partially missing, and liquid flows into the pressurizing chamber 109 from there.
Instead of eliminating the chipping, a hole (opening) is formed in the side surface of the liquid pressurizing chamber partition 112, from which the liquid flows into the pressurizing chamber 109.
You may make it flow in. (Embodiment 2) A second embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIG. 18A is a cross-sectional view, and FIG. 18B is a top view. Further, since the liquid ejecting apparatus of the present invention partially overlaps with the first embodiment, only the differences from the first embodiment will be described.

The structure of the liquid ejecting apparatus according to the second embodiment differs from that of the first embodiment in that the piezoelectric actuator 10
3 in that a resin sheet 104 is inserted between the piezoelectric actuator 103 and the low-rigidity layer 113 in order to separate the liquid passage 108 from the liquid existing in the liquid passage 108. The resin sheet 104 has a thickness of about 10 μm.

The injection method in the present embodiment is substantially the same as that in the first embodiment, and therefore, the differences will be described. When the piezoelectric actuator 103 bends downward, the resin film 104 having sufficiently low rigidity as compared with the piezoelectric actuator 103 is deformed upward, and the liquid flow path 108
In, the volume change hardly occurs. Therefore,
The pressure rise is very small. The resin sheet 1 to be inserted
When the piezoelectric actuator 104 has a sufficiently small bending rigidity compared to the piezoelectric actuator 103, the displacement of the piezoelectric actuator 103 due to the insertion of the resin sheet 104, the energy use efficiency decreases, or the pressure response characteristic deteriorates. It is possible to keep things to a minimum.

When the liquid ejecting apparatus of the present invention described above is used, it is possible to prevent the liquid from flowing out from the gap between the adjacent liquid ejecting apparatuses. This has the effect of eliminating the problem that the impedance between the diaphragms serving as the electrodes is lowered and the liquid that has flowed out causes the piezoelectric substrate 101 to be deteriorated.

In the present embodiment, it is assumed that the posture of the liquid ejecting apparatus is arbitrarily used, and the resin sheet 1 is used.
04 is used to prevent the liquid from flowing out, but if the liquid ejecting apparatus is used with the actuator facing upward, the resin sheet 104 may be removed and used in the same manner as in the first embodiment. In this case, the reaction force that the piezoelectric actuator 103 receives from the liquid in the liquid flow path 108 is further reduced, and the energy efficiency is further improved.

The liquid flow path 108 needs only to be filled to the extent that the liquid is supplied to the liquid pressurizing chamber 109 by the action of surface tension and pressure difference. Those with high compressibility of
The reaction force that the piezoelectric actuator 103 receives from the liquid in the liquid flow path 108 is further reduced, and the energy efficiency is further improved. (Embodiment 3) A third embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIG. FIG. 7 is a top view of the liquid ejecting apparatus, and a sectional view is substantially the same as FIG. 1A which is a sectional view of the first embodiment. Further, the present embodiment partially overlaps with the first embodiment, and thus only the main differences will be described. In the present embodiment, the liquid supply port 115 in the first embodiment is
15b, and the piezoelectric actuator 1 has a liquid flowing direction normal to that of the first embodiment.
03 has a sectional area of about 1/2. This allows
When the piezoelectric actuator 103 is displaced downward, that is, when the liquid pressurizing chamber 109 is in a high pressure state, the backflow of the liquid to the liquid flow path 108 is further reduced, and the energy efficiency is further increased. Further, although the re-supply capacity of the liquid is reduced by the pressure difference, the effect by the surface tension is increased, so that the liquid re-supply capacity is almost the same as that of the first embodiment. (Embodiment 4) A fourth embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIGS. FIG. 8A is a cross-sectional view of one element of the liquid ejecting apparatus according to the present embodiment, and FIG. 8B is a top view illustrating a part of the liquid ejecting apparatus according to the present embodiment. , Two liquid ejecting elements of the liquid ejecting apparatus are shown. An actual liquid ejecting apparatus has a form in which a plurality of liquid ejecting elements are connected. FIG. 8 is a perspective view of the liquid ejecting apparatus.

In FIGS. 8 and 9, reference numeral 201 denotes a laminated piezoelectric ceramic actuator. Reference numeral 202 denotes a stainless steel substrate. Reference numeral 105 denotes a liquid chamber forming substrate that mainly forms the liquid flow path 108 and the liquid pressurizing chamber 109, and reference numeral 106 denotes an ejection port forming substrate that forms the ejection port 110. Reference numeral 107 denotes a holding substrate for holding the actuator 103. Reference numeral 108 denotes a liquid flow path as described above. In addition, the liquid flow path 108 is
It is arranged on the left and right of. Reference numeral 109 denotes a liquid pressurizing chamber as described above. 110 is a liquid ejection port. Reference numeral 111 denotes a gap between the liquid pressurizing chamber partition 112 and the piezoelectric actuator 103. Reference numeral 114 denotes a polishing stopper substrate. 113 is a low-rigidity layer, for example,
8. A resin layer having a lower rigidity than the piezoelectric actuator 103. Reference numeral 115 denotes a liquid supply port for supplying a liquid from the liquid flow path 108 to the liquid pressurizing chamber 109.

Next, the structure and dimensions of the liquid ejecting apparatus according to the present embodiment will be described. The laminated piezoelectric ceramic actuator 201 and the stainless steel substrate 202 are bonded with an adhesive. As shown in FIG. 8, the laminated piezoelectric ceramic actuator 201 has a width of 5 mm,
The length is 2.3 mm and the thickness is 200 μm. The stainless steel substrate 202 has a thickness of 2 μm. The distance between adjacent liquid ejecting elements is about 79 μm, and 90 elements are arranged in a line per inch. The multilayer piezoelectric ceramic actuator 201 is supported at its upper end (not shown), and is also supported via a stainless steel substrate 202 on the low rigidity layer 113 and the upper surface of the liquid pressurizing chamber partition 112. Low rigidity layer 113 is 30μ thick
m, the rigidity of which is 1/10 that of the piezoelectric actuator 103 or the liquid chamber forming substrate 105.
It is as follows. Normally, the rigidity of the low-rigidity layer 113 is 1/5 or less of the greater of the rigidity of the piezoelectric actuator 103 or the liquid-chamber forming substrate 105, but is preferably 1/10 or less. . Other dimensions are the same as those of the first embodiment.

The liquid ejecting method of the present embodiment is substantially the same as that of the first embodiment, but the operation principle of the piezoelectric actuator is different since the piezoelectric actuator 103 has been changed to the laminated piezoelectric ceramic actuator 201. The structure and operation principle of the multilayer actuator 201 will be described with reference to FIG. In FIG. 10, (a) is a perspective view of the multilayer actuator 201, which has a structure in which a plurality of piezoelectric substrates having the length vibration mode described in the first embodiment are stacked. (B) is a top view, (c) is a front view, and a broken line shows a state of deformation of the multilayer actuator 201 when a positive voltage is applied between the electrodes 620a and 620b. (D) is also a front view, and a broken line similarly shows a state of deformation when a negative voltage is applied. Actually, since the stacked actuator 201 has its upper part, that is, the upper part in the top view (b) fixed by the holding substrate 107, it is deformed upward in the upper parts (c) and (d). Without
The lower side is deformed more. The reason why the stacked type is used will be described. To increase the electric field applied to the piezoelectric body by reducing the thickness of the piezoelectric substrate per sheet, and to increase the rigidity by increasing the thinning and lowering the rigidity to increase the actuator's power It is.

When the above-described liquid ejecting apparatus according to the present embodiment is used, the number of controllable gradations is 8 to 12, which is larger than that of the conventional piezoelectric type.

Next, the features and effects of the liquid ejecting apparatus according to the present embodiment will be described. The liquid ejecting apparatus according to the present embodiment has the same features and effects as those of the first embodiment, but additionally has the following differences. Since the laminated piezoelectric ceramic actuator 201 is used instead of the piezoelectric actuator 103 and the generated force can be increased, the energy use efficiency is further improved as compared with the first embodiment. In addition, the rigidity of the multilayer piezoelectric ceramic actuator 201 is larger than the rigidity of the piezoelectric actuator 103, so that the pressure response characteristic is dramatically improved,
This is advantageous for ejecting small droplets. With the above features, multi-gradation printing is of course possible,
In addition, a small diameter liquid can be ejected, and high-resolution printing can be performed. (Fifth Embodiment) A fifth embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIG. In the present embodiment, unlike the first embodiment or the fourth embodiment, an electromagnetic actuator is used as a liquid pressurizing unit. Next, the structure and dimensions of the liquid ejecting apparatus according to the present embodiment will be described. The electromagnetic actuator 401 and the stainless steel substrate 402 are bonded with an adhesive. The thickness of the stainless steel substrate 402 is 2 μm.
The stainless steel substrate 402 is fixed to a portion other than the liquid supply port 115 of the liquid pressurizing chamber partition portion 112 via the low rigidity layer 113. The thickness and rigidity of the low rigidity layer 113 are the same as in the first embodiment. The length of the electromagnetic actuator 401 is 5
mm, the liquid pressurizing chamber 109 has an outer shape of 200 μm long and 6 mm wide.
00μm, inner diameter 140μm, width 500μm, depth 40
It is 0 μm. The liquid flow path 108 is 5.5 mm long
And the depth is 200 μm. Jetting port forming substrate 106
Has a thickness of 80 μm, and the opening diameter of the injection port 110 is 90 μm. The liquid chamber forming substrate 105 and the ejection port forming substrate 106 are adhered by an adhesive.

The ejection method of the liquid ejection device according to the present embodiment is basically the same as that of the first embodiment, except that the pressurizing means is different.

The feature of the liquid ejecting apparatus according to the present embodiment is that the liquid pressurizing means is an electromagnetic actuator 401 which can obtain a larger pressing force and a larger displacement than a piezoelectric actuator.

As described above, in this embodiment, in addition to the effects described in the first to fourth embodiments,
Since the electromagnetic actuator can obtain a large displacement, there is an effect that it is very advantageous to eject a large droplet. (Embodiment 6) A sixth embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIG. The present embodiment partially overlaps with the third embodiment, so that differences will be particularly described. In the present embodiment, the third embodiment is different from the third embodiment in that
The size of the liquid pressurizing chamber 109, the arrangement interval of the liquid ejecting elements, and the shape of the liquid pressurizing chamber 109 are different. More specifically, the multilayer piezoelectric ceramic actuator 201
Has a width of 5 mm, a length of 2.3 mm, and a thickness of 100 μm. The spacing between adjacent elements is about 41 μm, and 180 elements are arranged in a line per inch. The liquid pressurizing chamber 109 has inner dimensions (FIG. 12).
(B)) is 400 μm wide, 60 μm long and 400 μm deep
m is a rectangular parallelepiped shape. The liquid pressurizing chamber partition portion 112 has an outer shape (FIG. 12B) of 500 μ
m, the width is 100 μm, and the portion other than the liquid supply port 115 is fixed to the stainless steel substrate 202 via the low rigidity layer 113. In addition, two liquid supply ports 115 are provided at left and right.

The ejection method of the liquid ejection device according to the present embodiment is substantially the same as that of the first to fourth embodiments. The features of the ejection device of the liquid ejection device according to the present embodiment will be described. In addition to the features described in the first to fourth embodiments, liquid ejecting elements are arranged at a narrow pitch, and the number of elements of the ejecting device is large. By adopting the present embodiment, the number of gradations is 8 to 12 values and compared with the conventional piezoelectric liquid ejecting apparatus,
Although improved, it is inferior to the third embodiment. However, since the liquid ejecting elements are arranged at a narrow pitch, high-resolution printing can be realized while suppressing a decrease in printing speed. (Seventh Embodiment) A seventh embodiment of the liquid ejecting apparatus according to the present invention will be described with reference to FIGS. 13A is a sectional view, and FIG. 13B is a top view. FIG. 13C is an enlarged view of the vicinity of the liquid pressurizing chamber 109, and FIG. 14 is a perspective view of the liquid ejecting apparatus. FIG.
3, and reference numerals 101 to 112, and 114 in FIG. 14 have substantially the same meanings as those in the first embodiment, except for those specified in the description of the present embodiment.

The structure and dimensions of the liquid ejecting apparatus according to the present embodiment will be described. The piezoelectric substrate 101 has a thickness of 33 μm, a length of 2 mm, and a width of 200 μm.
The actuator part of No. 2 has a thickness of 67 μm and a length of 2 m
m, and a width of 200 μm, and are bonded to each other with an adhesive to form a piezoelectric actuator 103. The distance between adjacent elements is about 79 μm, and 9
Zero elements are arranged. The resin sheet 104 has a thickness of about 5 μm and is bonded to the vibration plate 102 and the liquid chamber forming substrate 105 by an adhesive and pressure bonding. The liquid channel 108 has a length of 2 mm and a depth of 200 μm. The liquid pressurizing chamber 109 has an inner diameter of 140 μmφ and a depth of 400 μm, and the liquid pressurizing chamber partition 112 has a donut shape with an outer shape of 200 μm and an inner diameter of 140 μm when viewed from the top. The ejection port forming substrate 106 has a thickness of 4
At 0 μm, the opening diameter of the injection port 110 is 40 μm. Further, the liquid chamber forming substrate 105 and the injection port forming substrate 1
Reference numeral 06 is adhered by an adhesive. Also, the gap 111
, That is, the distance between the resin sheet 104 and the partition wall portion 112 of the liquid pressurizing chamber is about 10 μm when no voltage is applied to the piezoelectric actuator 103. The polishing stopper substrate 114 has the same thickness of 33 μm as the piezoelectric substrate 101.

The manufacturing method of the liquid ejecting apparatus according to the present embodiment is substantially the same as that of the first embodiment.

The liquid ejecting method of the liquid ejecting apparatus according to the present embodiment will be described with reference to FIG. FIG.
5A is a sectional view of the liquid ejecting element in a state where no voltage is applied, and FIG. 15B is a diagram in which a voltage is applied, the piezoelectric actuator 103 is displaced, and the liquid is ejected from the liquid ejecting port 110. FIG. 15C is a cross-sectional view of the liquid ejecting element at the time.
Means that the piezoelectric actuator 103 is a liquid pressure chamber partition part 11
FIG. 3 is an enlarged view of a liquid pressurizing chamber 109 portion when the liquid pressure chamber 2 comes closest to FIG. This will be described below. The liquid supplied from the liquid tank (not shown in the drawing) of the liquid ejecting apparatus to the liquid flow path 108 of each element is subjected to capillary action or liquid pressure through the gap 111 due to a pressure difference between the chambers. It is supplied to the chamber 109 (FIG. 15A). The pressure difference is generated by operating the piezoelectric actuator 103 or by using the liquid ejection port 110.
It is performed by suctioning from the like. When the piezoelectric actuator 103 is bent and displaced toward the liquid pressure chamber partition wall portion 112 side (downward), the length g of the gap 111 becomes smaller than the initial value. At this time, although there is a difference depending on the viscosity of the liquid and the physical properties of the partition wall material, when the value of g is approximately 10 to 2 μm, the liquid pressurizing chamber 109 is formed by the viscosity of the liquid filled in the gap 111. 108 (see FIG. 15C). At this time, the gap 111 is in a state of being filled with the liquid, and the thin liquid layer plays a role of a pressure wall for preventing pressure from leaking from the liquid pressurizing chamber 109 to the liquid flow path 108. That is, the liquid pressurizing chamber 1
09 is substantially blocked from the liquid flow path 108,
There is almost no pressure leakage to the liquid flow path 108, and only the pressure in the liquid pressurizing chamber 109 increases. By the above operation, the liquid is ejected from the liquid ejection port 110 (FIG. 15).
(B)). After the ejection, the pressure in the liquid pressurizing chamber 109 decreases, the piezoelectric actuator 103 is displaced upward, and the liquid is supplied again from the liquid flow path 108. The method of supplying the liquid to the liquid pressurizing chamber 109 is the same as in the first embodiment, but the liquid can be supplied more smoothly than in the first embodiment. In addition, as shown in FIG.
Another opening S may be provided in the liquid pressurizing partition wall portion 112 that forms 9.

When the liquid ejecting apparatus of the present embodiment described above is used, the modulation width becomes 100 or more and the number of controllable gradations becomes 32 or more, and the conventional piezoelectric type, the first comparative example, However, compared to the first embodiment, the size is dramatically increased.

The features and effects of the structure of the liquid ejecting apparatus according to the present embodiment described above will be described. The structural features of the liquid ejecting apparatus according to the present embodiment are the same as those described in the first embodiment, except that the piezoelectric actuator 103 and the liquid pressurizing chamber 109 are separated from each other with a predetermined gap. Is
The liquid pressurizing chamber 109 is fixed at a portion other than the partition wall constituting the inner wall. In addition, since the piezoelectric actuator 103 does not need to previously seal the inside of the liquid pressurizing chamber 109, the supporting method is not the full-circumferential support that normally supports the four sides, but the both-end support that can take a large displacement. That is possible. Also, as compared with the first embodiment, since the low-rigid layer 113 is not provided, the liquid pressurizing chamber 109 is in
08 and the liquid flow path 10
The pressure rise in 8 is even smaller. Therefore, the liquid flow path 1
The reaction force received from the liquid that hinders the displacement of the piezoelectric actuator 103 within 08 becomes even smaller than in the first embodiment.

With the above features, the energy use efficiency is increased and the modulation width can be increased. Further, since a large displacement characteristic can be obtained, it is advantageous for ejecting large droplets, and the width of modulation can be further increased. In addition, it is possible to increase the speed of switching from the low pressure state to the high pressure state in the liquid pressurizing chamber 109 despite the relatively low rigidity of the piezoelectric actuator 103. In other words, it is possible to improve the pressure response characteristics, and it is also possible to eject small droplets, thereby further widening the modulation range. In addition, since large displacement characteristics can be obtained, there is no need to precisely control displacement, so controllability is also improved. Further, due to the large pressure difference between the liquid flow path 108 and the liquid pressurizing chamber 109 after the ejection, the narrow gap 111 and the large effect due to the capillary phenomenon, etc.,
9, the supply of liquid is sufficiently overtaken even when the piezoelectric actuator 103 is driven at a high speed, and high-speed printing is possible. There is also an effect that defoaming becomes possible. Note that, even when the liquid ejecting apparatus according to the present embodiment is not used for multi-tone printing, there is also an effect that the power consumption of the liquid ejecting apparatus can be reduced due to its high energy use efficiency. Note that, in the present embodiment, the liquid does not need to be completely filled in the liquid flow path 108 as in the first embodiment, and it is sufficient that the liquid is supplied to the liquid pressurizing chamber 109. Good. In the present embodiment, unlike the first embodiment, since the low-rigid layer 113 does not exist, this effect is very large.

In Embodiments 1 to 7 described above, a stainless steel substrate is mainly used as diaphragm 102, but similar effects can be obtained by using other metal substrates. Further, even when a metal substrate is not used, a structure can be obtained in which a similar effect can be obtained by interposing a conductive material between the piezoelectric substrate 101 and the vibration plate 102.

In Embodiments 1 to 3 and Embodiment 7 described above, a unimorph actuator which is a piezoelectric actuator in a bending vibration mode is used as the liquid pressurizing member. Alternatively, a multimorph actuator having a structure in which a plurality of bimorph actuators are stacked may be used. As a result, if the outer shape is the same, the amount of displacement obtained is further increased, and it is possible to obtain more favorable large displacement characteristics.

The first to fourth embodiments, the sixth embodiment, or the seventh embodiment described above.
In the above, the piezoelectric actuator is used as the liquid pressurizing member, but the same effect can be obtained by using an actuator driven by another driving principle such as an actuator using electromagnetic force.

In the first to seventh embodiments described above, the liquid ejecting apparatus has a plurality of liquid ejecting elements connected in series. However, the number of liquid ejecting elements is not limited to this. If there is one, the same effect can be obtained.

The first to fourth embodiments, the sixth embodiment, or the seventh embodiment described above.
Although a piezoelectric ceramic is used as a constituent material of the piezoelectric actuator in the above, a piezoelectric single crystal material such as single crystal lithium niobate, single crystal lithium tantalate, single crystal potassium niobate may be used. Comparative Example A comparative example with the liquid ejecting apparatus according to the embodiment of the present invention will be described with reference to FIG. In this comparative example, the characteristics of a normal piezoelectric liquid ejecting apparatus are verified. In FIG. 19, reference numeral 701 denotes a piezoelectric substrate having a thickness and a length which are the same as those of the piezoelectric substrate
Same as 1. Further, unlike the piezoelectric substrate 101 in the seventh and twelfth embodiments, the piezoelectric substrate 701 is not separated for each element adjacent in the width direction and is held around the entire circumference of the piezoelectric substrate 701. In other words, it is natural that both ends are fixed, but the hatched portion in FIG. 19 is also fixed to the lower substrate. The actuator portion of the diaphragm 702 also has the same thickness and length as the diaphragm 102, and the piezoelectric substrate 701 and the diaphragm 702
Are bonded to each other with an adhesive, and the piezoelectric actuator 7
03 is formed. The distance between adjacent elements is about 79 μm, which is also the same as in the liquid ejecting apparatuses according to the seventh and twelfth embodiments. The liquid pressurizing chamber 709 has a length of 2
mm, and the depth is 200 μm. The opening of the injection port 710 is also the injection port 1 in the seventh and twelfth embodiments.
It has the same dimensions as 10.

In this comparative example, the sectional area of the pressure chamber 709 is equal to the area of the piezoelectric actuator 703. Further, in this comparative example, the piezoelectric actuator 703 is fixed to the partition 719 forming the pressurizing chamber 709.

Next, using the liquid ejecting apparatus of this comparative example,
A liquid injection experiment showed that the number of controllable gradations was 2
４4 values. However, the upper limit of the amplitude value of the applied voltage was set to Vmax. Fig. 19 shows only one comparative example.

The present invention is applicable not only to general inkjet printers but also to facsimile machines, word processors,
It may be used in combination with a device having a printing device such as a register.

Further, the present invention can be applied as an apparatus used in a production line, such as engraving and drawing on an industrial product, application of a chemical solution, and the like.
The recording medium of the present invention is not limited to paper, but may be metal, glass, resin, pottery, wood, cloth, leather, or the like.

[0072]

As is apparent from the above description,
By using the structure of the liquid ejecting apparatus and the ejecting method of the present invention, the energy use efficiency is increased, the liquid pressurizing member can be operated with a large displacement, and the response characteristic of the pressure in the liquid pressurizing chamber is improved. And a device having good controllability can be provided. From the above, it is possible to accurately eject a wide range of droplets, and both the modulation width and the number of gradations increase. Therefore, multi-tone printing can be realized. Further, by using the method for manufacturing a liquid ejecting apparatus according to the present embodiment, it is also possible to provide an inexpensive and high-performance liquid ejecting apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing a liquid ejecting apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a liquid ejecting apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a method of manufacturing the liquid ejecting apparatus according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a method of manufacturing the liquid ejecting apparatus according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the operating principle of a unimorph type piezoelectric actuator.

FIG. 6 is a diagram showing the principle of liquid ejection according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a liquid ejecting apparatus according to a third embodiment of the present invention.

FIG. 8 is a diagram illustrating a liquid ejecting apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing the vicinity of a liquid pressurizing chamber of a liquid ejecting apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing the operation principle of a multilayer piezoelectric actuator.

FIG. 11 is a diagram showing a liquid ejecting apparatus according to a fifth embodiment of the present invention.

FIG. 12 is a diagram illustrating a liquid ejecting apparatus according to a sixth embodiment of the present invention.

FIG. 13 is a diagram illustrating a liquid ejecting apparatus according to a seventh embodiment of the present invention.

FIG. 14 is a diagram illustrating a liquid ejecting apparatus according to a seventh embodiment of the present invention.

FIG. 15 is a diagram illustrating a liquid ejecting method of a liquid ejecting apparatus according to a seventh embodiment of the present invention.

FIG. 16 is a view showing the structure of a conventional thermal liquid ejecting apparatus and the principle of ejection.

FIG. 17 shows a structure of a conventional piezoelectric liquid ejecting apparatus, and
Diagram showing the principle of injection

FIG. 18 is a diagram illustrating a liquid ejecting apparatus according to a second embodiment of the present invention.

FIG. 19 is a diagram showing a comparative example.

[Explanation of symbols]

 101: piezoelectric ceramic substrate 102: diaphragm 103: piezoelectric actuator 104: resin sheet 105: liquid chamber forming substrate 106: ejection port forming substrate 107: holding substrate 108: liquid flow path 109: liquid pressurizing chamber 110: liquid Injection port

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Komatsu 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yoshihiro Tomita 1006 Odaka Kazama Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. ( 72) Inventor Kawasaki Osamu 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.F-term (reference) 2C057 AF33 AF39 AF52 AG12 AG39 AG40 AG43 AG44 AG47 AG51 AP75 BA04 BA14 CA01

Claims (10)

[Claims] At least a liquid pressurizing chamber, a liquid ejection port provided in a part of the liquid pressurizing chamber, a liquid pressurizing member disposed adjacent to the liquid pressurizing chamber, and the liquid A liquid flow path disposed adjacent to the pressurizing chamber, and by driving the liquid pressurizing member, by pressurizing the liquid supplied from the liquid flow path to the liquid pressurizing chamber, In the liquid ejecting apparatus that ejects liquid from the liquid ejecting port, an area in a cross section of the liquid pressurizing chamber, where a displacement direction of the liquid pressurizing member is a normal direction, is smaller than an area of the liquid pressurizing member. A liquid ejecting apparatus characterized by the above-mentioned. 2. The liquid pressurizing member is fixed at both ends of the liquid pressurizing member to portions other than a partition wall constituting the liquid pressurizing chamber. Liquid ejector. 3. The liquid pressurizing chamber has one or a plurality of openings, and all of the periphery of the opening existing at a position facing the liquid pressurizing member among the openings; The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is arranged so as to be separated from a lower surface of the liquid pressurizing member with a predetermined gap. 4. The liquid pressurizing chamber has one or a plurality of openings, and all or a part of a peripheral edge of the opening existing at a position facing the liquid pressurizing member among the openings. 2. The liquid ejecting apparatus according to claim 1, wherein the lower surface of the liquid pressurizing member is in contact with the lower surface of the liquid pressing member via a predetermined member. 5. The liquid ejecting apparatus according to claim 4, wherein the predetermined member is a member made of a material having a lower elastic modulus than a material forming the liquid pressurizing member. 6. The liquid ejecting apparatus according to claim 1, wherein said liquid pressurizing means is a piezoelectric actuator. 7. The liquid ejecting apparatus according to claim 6, wherein the piezoelectric actuator has a bimorph structure, a monomorph structure, or a unimorph structure in a bending vibration mode. 8. The liquid ejecting apparatus according to claim 6, wherein a main vibration mode of the piezoelectric actuator is a length vibration mode. 9. The liquid ejecting apparatus according to claim 6, wherein the piezoelectric material forming the piezoelectric actuator is a piezoelectric ceramic material. 10. A method for injecting liquid using the liquid ejecting apparatus according to claim 5, wherein the liquid pressurizing member is driven to deform an interposed member having a smaller rigidity than the liquid pressurizing member. A liquid ejecting method, wherein the liquid in the liquid pressurizing chamber is pressurized by changing a substantial volume of the liquid pressurizing chamber, and the liquid is ejected from the liquid ejecting port.