JP2001146025A - Attaching module body for detecting liquid, liquid container and ink cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the detection capacity of the consumption of a liquid utilizing a piezoelectric device. SOLUTION: An actuator 106 as a piezoelectric device has a function performing the conversion between electric energy and vibration energy and outputs the detection signal corresponding to the consumption of a liquid. An attaching module body 100, which is constituted by integrating the actuator 106 and an attaching member, is attached to an ink container. The attaching member has an opening cavity provided to its plate 110 and the opening cavity 112 is arranged at the position turned to the interior of a liquid container from the actuator 106.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting a change in acoustic impedance, and more particularly, a change in resonance frequency, thereby detecting a state of consumption of a liquid in a liquid container containing the liquid. More specifically, the present invention is applied to an ink jet recording apparatus that prints by ejecting ink droplets from nozzle openings by pressurizing ink in a pressure generating chamber by pressure generating means in accordance with print data by a pressure generating means. The present invention relates to a piezoelectric device provided in an ink cartridge to be used, and for detecting a consumption state of ink in the ink cartridge.

[0002]

2. Description of the Related Art As an example of a liquid container to which the present invention is applied, an ink cartridge mounted on an ink jet recording apparatus will be described. Generally, an ink jet recording apparatus includes a carriage equipped with an ink jet recording head having pressure generating means for pressurizing a pressure generating chamber, and a nozzle opening for discharging pressurized ink as ink droplets from the nozzle opening, And an ink tank for storing ink supplied to the recording head via a path, and is configured to be capable of continuous printing. Generally, the ink tank is configured as a cartridge detachable from the recording apparatus so that the user can easily replace the ink tank when the ink is consumed.

Conventionally, as a method of managing ink consumption of an ink cartridge, the count number of ink droplets ejected by a recording head and the amount of ink sucked in a maintenance process of a print head are integrated by software to calculate By controlling the ink consumption and attaching two electrodes for liquid level detection directly to the ink cartridge,
There has been known a method of managing ink consumption by detecting the point in time when a predetermined amount of ink is actually consumed.

However, the method of integrating the number of ink droplets ejected and the amount of sucked ink by software and managing the consumption of ink in a calculation method depends on the use environment, for example, the temperature and humidity in the use room, the ink cartridge, and the like. Due to the elapsed time after opening, the difference in the frequency of use on the user side, etc., the pressure inside the ink cartridge and the viscosity of the ink will change, and the error between the calculated ink consumption and the actual consumption will not be negligible. There was a problem that would occur. Further, when the same cartridge is once removed and then re-installed, the integrated count value is reset once, so that there is also a problem that the actual remaining amount of ink cannot be known at all.

On the other hand, the method of managing the time when ink is consumed by the electrode can detect the actual amount of ink consumption at one point, so that the remaining amount of ink can be managed with high reliability. However, in order to detect the liquid level of the ink, the ink must be conductive, which limits the type of ink used. Further, there is a problem that a liquid-tight structure between the electrode and the ink cartridge is complicated. Further, since a noble metal having high conductivity and high corrosion resistance is usually used as a material of the electrode, there is a problem that the manufacturing cost of the ink cartridge is increased. Further, since it is necessary to mount the two electrodes at different locations of the ink cartridge, there is a problem that the number of manufacturing steps is increased and the manufacturing cost is increased as a result.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a liquid container capable of accurately detecting a liquid consumption state and eliminating the need for a complicated sealing structure, which can solve the above-mentioned problems. Aim. Another object of the present invention is to provide an ink cartridge which can accurately detect the ink consumption state and does not require a complicated sealing structure.

The present invention particularly provides a technique for detecting the remaining amount of liquid using vibration, and improves such a detection technique. Note that the present invention is not limited to the ink cartridge, and is applicable to liquid detection of other liquid containers.

[0008] The above object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.

[0009]

One embodiment of the present invention is a module for detecting a liquid. This module body
Including a piezoelectric device and a mounting member. The piezoelectric device is used to detect a consumption state of a liquid in a liquid container. The attachment member is integrated with the piezoelectric device, and attaches the piezoelectric device to the liquid container. The mounting member is particularly provided with an open cavity. The opening cavity is provided at a position facing the piezoelectric device so as to communicate with the inside of the liquid container. Preferably, the opening cavity is disposed at a position facing the inside of the liquid container from the piezoelectric device, and is provided so as to communicate with the inside of the liquid container.

When liquid consumption has not yet progressed, the inside and outside of the open cavity are filled with liquid. On the other hand, in a state where the liquid consumption is advanced, the liquid level is lowered to expose the open cavity, and a substantially constant amount of liquid remains in the open cavity. In these states, by utilizing the fact that the output signals of the piezoelectric device are different, it is possible to appropriately detect the liquid consumption state.

According to the present invention, by providing the cavity, it is possible to prevent erroneous detection due to waving of the liquid or the like.

Further, according to the present invention, by providing the opening cavity, the number of members interposed between the piezoelectric device and the liquid can be reduced or the thickness of the members can be reduced, so that the liquid consumption state can be detected more reliably. it can.

According to the present invention, an appropriate liquid sealing state can be ensured by locally providing the open cavity. This avoids improper exposure of the piezoelectric device to liquids. This is particularly effective for conductive liquids such as ink.

[0014] Preferably, the liquid consumption state is detected based on a change in acoustic impedance according to the liquid consumption state using the piezoelectric device. Preferably, the piezoelectric device outputs a signal indicating a residual vibration state after the generation of the vibration. The residual vibration of the piezoelectric device changes according to the amount of the surrounding liquid. For example, the residual vibration state differs between when a large amount of liquid exists around and when a small amount of liquid exists around. This is based on the change in acoustic impedance according to the state of liquid consumption. Therefore, the liquid consumption state is detected using the fact that the residual vibration state changes according to the liquid consumption state.

Here, it is the limited amount of liquid near the piezoelectric device that substantially affects the residual vibration. According to the present invention, by providing the opening cavity, the number of members interposed between the piezoelectric device and the liquid can be reduced or the thickness of the members can be reduced. Therefore, a limited amount of liquid that affects the residual vibration approaches or contacts the piezoelectric device. Thereby, the change in the residual vibration according to the liquid consumption state becomes clearer, so that the liquid consumption state can be detected more reliably.

The piezoelectric device may generate an elastic wave through the opening cavity and output a signal corresponding to the reflected wave returning through the opening cavity. Also in this case, the provision of the open cavity allows the vibration to be transmitted well between the piezoelectric device and the liquid, so that the detection capability can be improved. How the piezoelectric device functions to detect the liquid consumption state may be determined according to the specifications of the liquid container, the required measurement accuracy, and the like.

When a liquid is held in the opening cavity in a predetermined liquid consumption state as a detection target, a detection signal indicating a residual vibration state corresponding to the liquid in the opening cavity. May occur.

Preferably, the opening cavity has a shape for holding a liquid in a predetermined liquid state. Preferably, the opening cavity may have a shape for holding a liquid even in a predetermined liquid consumption state of a detection target.

Preferably, the piezoelectric device includes a lower electrode, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer, wherein the area of the open cavity is smaller than the piezoelectric layer. Is set to be equal to or larger than the area of the overlapping portion of the lower electrode and the lower electrode.

Preferably, the cavity depth of the opening cavity is set smaller than the minimum width of the cavity opening. Preferably, the cavity depth is not more than 1/3 of the minimum width of the cavity opening. If the cavity is circular, the minimum opening width is the opening size (opening diameter).

Preferably, the open cavity has a substantially symmetric shape with respect to the center of vibration of the piezoelectric device. Preferably, the open cavity is substantially circular.

Preferably, the opening area of the opening cavity on the container inner side is set to be larger than the opening area on the piezoelectric element side. It is preferable that the opening dimension of the piezoelectric element side is larger than that of the inside of the container. With such a configuration, the open cavity has a shape expanding toward the inside of the container. The peripheral surface of the opening cavity may have a tapered shape.
The peripheral surface of the open cavity may have a step shape.

A communication groove communicating with the open cavity is
It may be provided at a location facing the inside of the container. The communication groove may be provided along a direction from the opening cavity toward a supply port through which the liquid container supplies liquid to the outside.

[0024] The mounting member may be fitted into a through hole provided in the liquid container. The piezoelectric device may have a concave portion communicating with the open cavity of the mounting member.

A liquid absorber may be provided in the vicinity of the opening cavity. The liquid absorber may suck out the liquid in the open cavity. The liquid absorber may be composed of a porous member.

A liquid absorber may be provided in the opening cavity. The liquid absorber may hold a liquid. The liquid absorber may be composed of a porous member.

The mounting module may be detachably mounted on the liquid container.

Another embodiment of the present invention is a liquid container provided with the above-described mounting module for detecting liquid. The liquid container may be an ink cartridge mounted on an ink jet recording apparatus.

The above summary of the present invention does not list all of the necessary features of the present invention, and sub-combinations of these features may also constitute the present invention.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the claimed invention and have the features described in the embodiments. Not all combinations are essential to the solution of the invention.

First, the principle of the present embodiment will be described. In the present embodiment, the present invention is applied to a technique for detecting an ink consumption state in an ink container. The ink consumption state is detected using a piezoelectric device. The piezoelectric device outputs a signal corresponding to the ink consumption state by converting between electric energy and vibration energy.

One of the detection principles utilizes acoustic impedance. Preferably, a residual vibration state after the piezoelectric device generates vibration is obtained from an output signal of the piezoelectric device.
The residual vibration changes according to the amount of surrounding ink. This is based on a change in acoustic impedance according to the ink consumption state. Therefore, the consumption state is detected using the fact that the residual vibration state changes according to the ink consumption state.

According to another detection principle, the piezoelectric device generates an elastic wave through the opening cavity and outputs a signal corresponding to the reflected wave returning through the opening cavity. A change in the reflected wave according to the ink consumption state is detected. How the piezoelectric device functions to detect the ink consumption state may be determined according to the specifications of the ink cartridge, the required measurement accuracy, and the like.

The piezoelectric device is provided at a liquid level position in a predetermined target ink consumption state as a detection target. This makes it possible to detect the presence or absence of liquid level passage.

In this embodiment, a mounting module is constituted by the piezoelectric device and the mounting member. In particular, the mounting member is provided with an open cavity. The open cavity is
When the module is mounted, it is arranged at a position facing the inside of the ink container from the piezoelectric device, and communicates with the inside of the container. The open cavity faces the piezoelectric device, in particular the vibrating part thereof.

The provision of such an open cavity has the following advantages. In a state where the ink consumption has not yet progressed, the ink level is high, so that the inside and outside of the open cavity is filled with the ink. On the other hand, as ink consumption increases, the liquid level decreases and the open cavity is exposed. At this time, a substantially constant small amount of ink remains in the open cavity. In these two states, the above-described residual vibration and the like are different, so that the output signals of the piezoelectric device are different. By utilizing this, the ink consumption state can be suitably detected.

Preferably, the detection characteristic when a small amount of ink is held in the cavity is grasped in advance. Alternatively, the detection characteristics when the ink is inside and outside the cavity may be grasped in advance. Of course, the detection characteristics of both states may be grasped.

According to the present embodiment, as described below,
By providing the cavity, it is possible to prevent erroneous detection due to ink undulation or the like.

Further, according to the present embodiment, the provision of the opening cavities allows the number of members interposed between the piezoelectric device and the ink to be reduced or the thickness of the members to be reduced, so that the ink consumption state can be more reliably achieved. Can be detected.

For example, considering the principle of detection utilizing residual vibration, it is the limited amount of ink near the piezoelectric device that substantially affects residual vibration. This limited amount of ink approaches or contacts the piezoelectric device due to the provision of the open cavity. Thereby, the change in the residual vibration according to the ink consumption state becomes clearer, so that the ink consumption state can be detected more reliably.

Also in the case of utilizing the elastic wave and the reflected wave, the provision of the open cavity allows the vibration to be transmitted well between the piezoelectric device and the ink, so that the detection capability can be improved.

Further, according to the present embodiment, since the cavity is provided locally, the ink can be appropriately sealed. This protects the piezoelectric device from the ink. It is possible to effectively prevent the insulating state of the piezoelectric device from being damaged by the conductive ink.

Hereinafter, the present embodiment will be described more specifically with reference to the drawings. First, the basics of a technique for detecting ink consumption based on vibration using a piezoelectric device will be described. Following this, various applications of the detection technology will be described. In developing these descriptions, the characteristic mounting module body with a cavity and other variations of the present embodiment will be described.

Here, in the present embodiment, as one mode of the piezoelectric device, an “actuator (typically, FIG.
0, reference numeral 106) "and" elastic wave generating means (typically, FIG. 1, reference numeral 3). However, these are only one form of the piezoelectric device.
A configuration in which another component is added to the actuator may be used, or a configuration in which some components are removed from the actuator may be used. The piezoelectric device may be a piezoelectric element alone.

[Detection of Ink Consumption Using Piezoelectric Device]
The basic concept of the present invention is that the state of liquid in a liquid container (including the presence or absence of liquid in a liquid container, the amount of liquid, the liquid level of liquid, the type of liquid, and the composition of liquid) is obtained by utilizing the vibration phenomenon. Is to detect. There are several methods for detecting the state of the liquid in the liquid container using a specific vibration phenomenon. For example, the elastic wave generating means generates an elastic wave to the inside of the liquid container and receives a reflected wave reflected by the liquid surface or an opposing wall to detect a medium in the liquid container and a change in its state. There is a way. Alternatively, there is a method of detecting a change in acoustic impedance from the vibration characteristics of a vibrating object. As a method of utilizing the change in acoustic impedance, a vibrating portion of a piezoelectric device or an actuator having a piezoelectric element is vibrated, and then, a back electromotive force generated by residual vibration remaining in the vibrating portion is measured, thereby obtaining a resonance frequency or a reverse frequency. A method of detecting the change in acoustic impedance by detecting the amplitude of the electromotive force waveform, or measuring the impedance characteristic or admittance characteristic of the liquid by using a measuring instrument, for example, an impedance analyzer such as a transmission circuit, and measuring the change in the current value or voltage value or There is a method of measuring a change in current value or voltage value with frequency when vibration is applied to a liquid. The details of the operation principle of the elastic wave generating means and the piezoelectric device or the actuator will be described later.

FIG. 1 is a sectional view of an embodiment of an ink cartridge for a single color, for example, black ink to which the present invention is applied. The ink cartridge of FIG. 1 is based on the method of receiving the reflected wave of the elastic wave and detecting the position of the liquid surface in the liquid container and the presence or absence of the liquid, among the methods described above. Elastic wave generating means 3 is used as means for generating and receiving elastic waves. An ink supply port 2 that is connected to an ink supply needle of a recording apparatus is provided in a container 1 that stores ink. Elastic wave generating means 3 is attached to the outside of the bottom surface 1a of the container 1 so that elastic waves can be transmitted to the ink inside via the container. At the stage when the ink K is almost consumed, that is, when the ink is near the end,
The elastic wave generating means 3 is provided at a position slightly higher than the ink supply port 2 in order to change the transmission of the elastic wave from ink to gas. The receiving means may be separately provided, and the elastic wave generating means 3 may be used simply as the generating means.

The ink supply port 2 has a packing 4 and a valve body 6.
Is provided. As shown in FIG. 3, the packing 4 is engaged with the ink supply needle 32 communicating with the recording head 31 in a liquid-tight manner. The valve body 6 is always in elastic contact with the packing 4 by the spring 5. When the ink supply needle 32 is inserted,
The valve 6 is pushed by the ink supply needle 32 to open the ink flow path, and the ink in the container 1 is supplied to the recording head 31 via the ink supply port 2 and the ink supply needle 32. Container 1
On the upper wall, a semiconductor storage means 7 which stores information on the ink in the ink cartridge is mounted.

FIG. 2 is a rear perspective view showing an embodiment of an ink cartridge containing a plurality of types of ink. The container 8 is divided into three ink chambers 9, 10 and 11 by partition walls. Ink supply ports 12, 13 and 14 are formed in each ink chamber. On the bottom surface 8a of each of the ink chambers 9, 10 and 11, elastic wave generating means 15, 16 and 17 are attached via a container 8 so that elastic waves can be transmitted to the ink contained in each ink chamber. ing.

FIG. 3 is a sectional view showing an embodiment of a main part of an ink jet recording apparatus suitable for the ink cartridge shown in FIGS. The carriage 30 that can reciprocate in the width direction of the recording paper has a sub-tank unit 33, and the recording head 31 is provided on the lower surface of the sub-tank unit 33. The ink supply needle 32 is provided on the ink cartridge mounting surface side of the sub tank unit 33.

FIG. 4 is a sectional view showing details of the sub tank unit 33. As shown in FIG. The sub-tank unit 33 includes an ink supply needle 32, an ink chamber 34, a membrane valve 36, and a filter 3.
Seven. The ink supplied from the ink cartridge via the ink supply needle 32 is stored in the ink chamber 34. The membrane valve 36 is connected to the ink chamber 34 and the ink supply path 35.
It is designed to open and close by the pressure difference between The ink supply path 35 communicates with the recording head 31 and has a structure in which ink is supplied to the recording head 31.

As shown in FIG. 3, when the ink supply port 2 of the container 1 is inserted into the ink supply needle 32 of the sub-tank unit 33, the valve 6 moves backward against the spring 5 to form an ink flow path. The ink in the container 1 flows into the ink chamber 34. At the stage when the ink is filled in the ink chamber 34, a negative pressure is applied to the nozzle opening of the
After the ink is filled in 1, the recording operation is performed.

When the ink is consumed in the recording head 31 by the recording operation, the pressure on the downstream side of the membrane valve 36 decreases, so that the membrane valve 36 is separated from the valve body 38 and opened as shown in FIG. . When the membrane valve 36 is opened, the ink chamber 3 is opened.
4 is supplied to the recording head 31 via the ink supply path 35.
Flow into As the ink flows into the recording head 31, the ink in the container 1 flows into the sub tank unit 33 via the ink supply needle 32.

During the operation of the recording apparatus, a drive signal is supplied to the elastic wave generating means 3 at a predetermined detection timing, for example, at a constant period. The elastic wave generated by the elastic wave generating means 3 propagates on the bottom surface 1a of the container 1, is transmitted to the ink, and propagates the ink.

By sticking the elastic wave generating means 3 to the container 1, the ink cartridge itself can be provided with a function of detecting the remaining amount. According to the present invention, it is not necessary to embed an electrode for liquid level detection at the time of molding the container 1,
The injection molding process is simplified, liquid leakage from the electrode embedding region is eliminated, and the reliability of the ink cartridge can be improved.

FIG. 5 shows the elastic wave generating means 3, 15, 16,
And 17 are shown. The fixed substrate 20 is formed of a material such as ceramic that can be fired. First, FIG.
As shown in (I), a conductive material layer 21 to be one electrode is formed on the surface of the fixed substrate 20. Next, as shown in FIG. 5 (II), a green sheet 22 of a piezoelectric material is overlaid on the surface of the conductive material layer 21. Next, as shown in FIG. 5 (III), the green sheet 22 is formed into a predetermined shape by a press or the like into the shape of a vibrator, air-dried, and then fired at a firing temperature, for example, 1200 ° C. Next, FIG. 5 (IV)
As shown in (2), a conductive material layer 23 serving as the other electrode is formed on the surface of the green sheet 22 and is polarized so as to be able to flex and vibrate. Finally, as shown in FIG.
0 is cut for each element. By fixing the fixed substrate 20 to a predetermined surface of the container 1 with an adhesive or the like, the elastic wave generating means 3 is fixed to the predetermined surface of the container 1, and an ink cartridge with a remaining amount detection function is completed.

FIG. 6 shows another embodiment of the elastic wave generating means 3 shown in FIG. In the embodiment of FIG. 5, the conductive material layer 21 is used as a connection electrode. On the other hand, in the embodiment of FIG. 6, the connection terminals 21a and 23a are formed at positions above the surface of the piezoelectric material layer constituted by the green sheet 22 by soldering or the like. Connection terminal 21a
And 23a, the elastic wave generating means 3 can be directly mounted on the circuit board, and the lead wires need not be routed.

Incidentally, an elastic wave is a type of wave that can propagate using a gas, a liquid, and a solid as a medium.
Therefore, the wavelength, amplitude, phase,
The frequency, propagation direction, propagation speed, etc. change. On the other hand, the state and characteristics of the reflected wave of the elastic wave also differ depending on the change of the medium. Therefore, it is possible to know the state of the medium by using the reflected wave that changes due to the change in the medium through which the elastic wave propagates. When the state of the liquid in the liquid container is detected by this method, for example, an elastic wave transceiver is used. To explain by taking the form of FIGS. 1 to 3 as an example, the transceiver first applies an elastic wave to a medium, for example, a liquid or a liquid container, and the elastic wave propagates through the medium and reaches the surface of the liquid. Since the surface of the liquid has a boundary between the liquid and the gas, the reflected wave is returned to the transceiver. The transceiver receives the reflected wave, and the transmitter or receiver and the surface of the liquid are determined based on the travel time of the reflected wave and the attenuation rate of the elastic wave generated by the transmitter and the amplitude of the reflected wave reflected by the surface of the liquid. And the distance can be measured. By utilizing this, the state of the liquid in the liquid container can be detected. The elastic wave generation means 3 may be used alone as a transceiver in a method utilizing a reflected wave due to a change in a medium through which the elastic wave propagates, or may be separately provided with a dedicated receiver.

As described above, the elastic wave generated by the elastic wave generating means 3 and propagating in the ink liquid is transmitted to the elastic wave generating means 3 by the reflected wave generated on the ink liquid surface depending on the density and the liquid level of the ink liquid. Arrival time changes. Therefore, when the composition of the ink is constant, the arrival time of the reflected wave generated on the surface of the ink liquid depends on the amount of the ink.
Therefore, the amount of ink can be detected by detecting the time from when the elastic wave generating means 3 generates the elastic wave to when the reflected wave from the ink surface reaches the elastic wave generating means 3. In addition, since the elastic waves vibrate particles included in the ink, in the case of a pigment-based ink using a pigment as a colorant, it contributes to preventing precipitation of the pigment and the like.

By providing the elastic wave generating means 3 in the container 1, when the ink in the ink cartridge is reduced to near the ink end due to the printing operation or the maintenance operation, the reflected wave cannot be received by the elastic wave generating means 3. Can determine that the ink is near the end and prompt the user to replace the ink cartridge.

FIG. 7 shows another embodiment of the ink cartridge of the present invention. A plurality of elastic wave generating means 41 to 44 are provided on the side wall of the container 1 at intervals in the vertical direction. The ink cartridge shown in FIG.
The presence or absence of ink at the level of the mounting position of each of the elastic wave generating means 41 to 44 can be detected based on whether or not ink exists at each of the positions 1 to 44. For example, when the water level of the ink is at a level between the elastic wave generators 44 and 43, the elastic wave generator 44 detects that there is no ink, and the elastic wave generators 41, 42, and 43 detect the ink level. Since it is detected that there is, the water level of the ink is at a level between the elastic wave generating means 44 and 43. Therefore, by providing the plurality of elastic wave generating means 41 to 44, the remaining amount of ink can be detected stepwise.

FIGS. 8 and 9 show still another embodiment of the ink cartridge of the present invention. In the embodiment shown in FIG. 8, the bottom surface 1a is formed obliquely in the vertical direction.
The elastic wave generating means 65 is attached to the second. In the embodiment shown in FIG. 9, the elastic wave generating means 66 extending in the vertical direction is provided near the bottom surface of the side wall 1b.

According to the embodiment of FIGS. 8 and 9, when the ink is consumed and a part of the elastic wave generating means 65 and 66 is exposed from the liquid surface, the elastic wave generating means 65 and 66 are turned off.
The arrival time and acoustic impedance of the reflected wave of the generated elastic wave continuously change in accordance with the liquid level changes Δh1 and Δh2. Therefore, by detecting the arrival time of the reflected wave of the elastic wave or the degree of change in the acoustic impedance, it is possible to accurately detect the process from the ink near-end state of the remaining ink amount to the ink end.

In the above-described embodiment, an example has been described in which an ink cartridge is of the type in which ink is directly stored in a liquid container. As another embodiment of the ink cartridge, the above-described elastic wave generating means may be mounted on an ink cartridge of a type in which a porous elastic body is loaded in the container 1 and the porous elastic body is impregnated with liquid ink. Further, in the above-described embodiment, the use of the flexural vibration type piezoelectric vibrator suppresses the size increase of the cartridge.
It is also possible to use a vertical vibration type piezoelectric vibrator. Furthermore, in the above-described embodiment, the same elastic wave generating means transmits and receives elastic waves. In another embodiment, the remaining amount of ink may be detected by using different elastic wave generating means for transmitting and receiving waves.

FIG. 10 shows still another embodiment of the ink cartridge of the present invention. A plurality of elastic wave generating means 65a, 65b, and 65c are provided in the container 1 at intervals in the vertical direction on a bottom surface 1a formed obliquely in the vertical direction. According to this embodiment, the plurality of elastic wave generating means 65
a, 65b, and 65c, depending on whether or not ink exists at each position,
a, at the level of the mounting position of 65b and 65c,
The arrival times of the reflected waves of the elastic waves to the respective elastic wave generating means 65a, 65b and 65c are different. Therefore, each of the elastic wave generating means 65 is scanned, and the elastic wave generating means 65 is scanned.
a, 65b and 65c, by detecting the arrival times of the reflected waves of the elastic waves, the respective elastic wave generating means 6
It is possible to detect the presence or absence of ink at the level of the mounting position of 5a, 65b and 65c. Therefore, the remaining amount of ink can be detected stepwise. For example, the ink level is changed to the elastic wave generating means 65b and the elastic wave generating means 65c.
The elastic wave generating means 65c detects the absence of ink, while the elastic wave generating means 65b and 65b
a detects that ink is present. By comprehensively evaluating these results, it is understood that the ink liquid level is located between the elastic wave generating means 65b and the elastic wave generating means 65c.

FIG. 11 shows still another embodiment of the ink cartridge of the present invention. The ink cartridge shown in FIG. 11 uses a plate 67 to increase the intensity of the reflected wave from the liquid surface.
Is attached to the float 68 to cover the ink liquid surface. The plate 67 is formed of a material having high acoustic impedance and ink resistance, for example, a ceramic plate.

FIG. 12 shows another embodiment of the ink cartridge shown in FIG. In the ink cartridge of FIG. 12, the plate 67 is floated in order to increase the intensity of the reflected wave from the liquid surface, similarly to the ink cartridge of FIG.
8 to cover the ink liquid level. FIG. 12 (A)
The elastic wave generating means 65 is fixed to the bottom surface 1a formed obliquely in the vertical direction. When the remaining amount of ink is reduced and the elastic wave generating means 65 is exposed from the liquid surface, the elastic wave generating means 65 of the reflected wave of the elastic wave generated by the elastic wave generating means 65.
Since the arrival time changes, the presence or absence of ink at the level of the mounting position of the elastic wave generating means 65 can be detected. Since the elastic wave generating means 65 is mounted on the bottom surface 1a which is formed obliquely in the vertical direction, some ink remains in the container 1 even after the elastic wave generating means 65 detects that there is no ink. Thus, the remaining ink amount at the time of the ink near end can be detected.

FIG. 12 (B) shows a case 1 in which a plurality of elastic wave generating means 65a, 65b and 65c are provided on a bottom surface 1a which is formed obliquely in the up-down direction and at intervals in the up-down direction. . According to the embodiment of FIG. 12B, depending on whether or not ink exists at each position of the plurality of elastic wave generating means 65a, 65b, and 65c, each of the elastic wave generating means 65a, 65b, and 65c is determined. The arrival times of the reflected waves to the elastic wave generating means 65a, 65b and 65c at the level of the mounting position are different. Therefore, by scanning each elastic wave generating means 65 and detecting the arrival time of the reflected wave at each elastic wave generating means, the presence or absence of ink at the level of the mounting position of each elastic wave generating means 65a, 65b and 65c is detected. Can be detected. For example, when the ink liquid level is at a level between the elastic wave generating means 65b and the elastic wave generating means 65c, the elastic wave generating means 65c detects the absence of ink, while the elastic wave generating means 65c
b and 65a detect that there is ink. By comprehensively evaluating these results, the ink liquid level is changed to the elastic wave generation means 65.
It can be seen that it is located between b and the elastic wave generating means 65c.

FIG. 13 shows still another embodiment of the ink cartridge of the present invention. The ink cartridge shown in FIG. 13A has a through hole 1 c provided inside the container 1.
Ink absorber 74 so that at least a part thereof faces
Is arranged. The elastic wave generating means 70 includes the through-hole 1
c, and is fixed to the bottom surface 1a of the container 1 so as to face c. The ink cartridge shown in FIG.
The ink absorber 75 is arranged so as to face the groove 1h formed to communicate with the ink.

According to the embodiment shown in FIG.
When the ink inside is consumed and the ink absorbers 74 and 75 are exposed from the ink, the ink of the ink absorbers 74 and 75 flows out by its own weight and supplies the ink to the recording head 31. When the ink is exhausted, the ink absorber 74
And 75 suck up the ink remaining in the through hole 1c, so that the ink is completely discharged from the concave portion of the through hole 1c. Therefore, the state of the reflected wave of the elastic wave generated by the elastic wave generating means 70 at the time of ink end changes, so that the ink end can be detected more reliably.

FIG. 14 shows a plan view of still another embodiment of the through hole 1c. As shown in FIGS. 14A to 14C, the planar shape of the through-hole 1c may be any shape such as a circle, a rectangle, and a triangle as long as the shape can attach the elastic wave generating means. .

FIG. 15 shows a cross section of another embodiment of the ink jet recording apparatus of the present invention. FIG. 15A shows a cross section of only the ink jet recording apparatus. FIG. 15 (B)
Indicates that the ink cartridge 27
2 shows a cross section when No. 2 is mounted. The carriage 250 that can reciprocate in the width direction of the inkjet recording paper has a recording head 252 on the lower surface. The carriage 250 has a sub tank unit 256 on the upper surface of the recording head 252. The sub tank unit 256 has the same configuration as the sub tank unit 33 shown in FIG. The sub tank unit 256 has an ink supply needle 254 on the mounting surface side of the ink cartridge 272. Carriage 250
Are provided in the area where the ink cartridge 272 is mounted so as to face the bottom of the ink cartridge 272.
8 The protrusion 258 has elastic wave generation means 260 such as a piezoelectric vibrator.

FIG. 16 shows an embodiment of an ink cartridge suitable for the recording apparatus shown in FIG. FIG. 16 (A)
Indicates an embodiment of an ink cartridge for single color, for example, black ink. The ink cartridge 272 of the present embodiment has a container 274 for storing ink, and an ink supply port 276 joined to the ink supply needle 254 of the recording apparatus. The container 274 has a concave portion 278 that engages with the convex portion 258 on the bottom surface 274a. The recess 278 accommodates an ultrasonic transmission material, for example, a gelling material 280.

The ink supply port 276 has a packing 282,
It has a valve body 286 and a spring 284. Packing 282
Engage with the ink supply needle 254 in a liquid-tight manner. Valve body 286
Is always in elastic contact with the packing 282 by the spring 284. When the ink supply needle 254 is inserted into the ink supply port 276, the valve 286 is pushed by the ink supply needle 254 to open the ink flow path. At an upper portion of the container 274, a semiconductor storage unit 288 storing information on ink and the like of the ink cartridge 272 is mounted.

FIG. 16B shows an embodiment of an ink cartridge containing a plurality of types of ink. Container 290
Is divided into a plurality of areas by the wall, that is, three ink chambers 2.
92, 294, and 296. Each of the ink chambers 292, 294, and 296 is provided with an ink supply port 29.
8, 300 and 302. The bottom surface 29 of the container 290
In the region opposing each of the ink chambers 292, 294, and 296, gelling materials 304, 306, and 308 for transmitting the elastic waves generated by the elastic wave generating means 260 are provided in cylindrical concave portions 310, 312, 314.

When the ink supply port 276 of the ink cartridge 272 is inserted into the ink supply needle 254 of the sub tank unit 256 as shown in FIG.
6 retreats against the spring 284 to form an ink flow path, so that the ink in the ink cartridge 272 flows into the ink chamber 262. At the stage when the ink is filled in the ink chamber 262, a negative pressure is applied to the nozzle openings of the recording head 252 to fill the recording head 252 with the ink, and then the recording operation is performed. When ink is consumed in the recording head 252 by the recording operation, the pressure on the downstream side of the membrane valve 266 decreases, and the membrane valve 266 is separated from the valve body 270 and opened. The ink in the ink chamber 262 flows into the recording head 252 by opening the membrane valve 266. The ink in the ink cartridge 272 flows into the sub-tank unit 256 as the ink flows into the recording head 252.

During the operation of the recording apparatus, a drive signal is supplied to the elastic wave generating means 260 at a predetermined detection timing, for example, at a constant cycle. The elastic wave generated by the elastic wave generating means 260 is radiated from the convex portion 258, propagates through the gelling material 280 on the bottom surface 274a of the ink cartridge 272, and is transmitted to the ink in the ink cartridge 272. In FIG. 15, the carriage 250 is provided with the elastic wave generating means 260, but the elastic wave generating means 260 may be provided in the sub tank unit 256.

Since the elastic wave generated by the elastic wave generating means 260 propagates in the ink liquid, the reflected wave reflected on the liquid surface arrives at the elastic wave generating means 260 depending on the density of the ink liquid and the liquid level of the ink. Time to change. Therefore, when the composition of the ink is constant, the arrival time of the reflected wave generated on the liquid surface depends only on the ink amount. Therefore, the amount of ink in the ink cartridge 272 can be detected by detecting the time until the reflected wave from the ink liquid surface after the excitation of the elastic wave generating means 260 reaches the elastic wave generating means 260. Further, the elastic wave generated by the elastic wave generating means 260 vibrates the particles contained in the ink, so that the precipitation of the pigment or the like is prevented.

When the ink in the ink cartridge 272 decreases to near the ink end due to the printing operation or the maintenance operation, and the reflected wave from the ink liquid surface after the elastic wave is generated by the elastic wave generating means 260 cannot be received. , The ink cartridge 272 can be replaced. When the ink cartridge 272 is not mounted on the carriage 250 as specified, the propagation form of the elastic wave by the elastic wave generating means 260 changes extremely. By utilizing this, when an extreme change in the elastic wave is detected, an alarm can be issued to urge the user to check the ink cartridge 272.

The arrival time of the reflected wave of the elastic wave generated by the elastic wave generating means 260 to the elastic wave generating means 260 depends on the container 2
74 is affected by the density of the ink contained in the ink. Since the ink density may differ depending on the type of ink, the data relating to the type of ink contained in the ink cartridge 272 is stored in the semiconductor storage unit 288, and a detection sequence corresponding to the data is executed. The amount can be detected more accurately.

FIG. 17 shows an ink cartridge 2 of the present invention.
72 shows another embodiment of the present invention. In the ink cartridge 272 shown in FIG. 17, the bottom surface 274a is formed obliquely in the vertical direction. The ink cartridge 272 in FIG.
When the remaining amount of ink becomes small and a part of the irradiation area of the elastic wave of the elastic wave generating means 260 is exposed from the ink surface, the reflected wave of the elastic wave generated by the elastic wave generating means 260 is transmitted to the elastic wave generating means 260. The arrival time is the change Δh1 in the ink level.
Changes continuously in response to Δh1 is the gelling material 28
The difference between the heights of the bottom surface 274a at both ends of 0 is shown. Therefore, by detecting the arrival time of the reflected wave to the elastic wave generating means 260, the process from the ink near end state to the ink end can be accurately detected.

FIG. 18 shows an ink cartridge 2 according to the present invention.
72 shows still another embodiment of the inkjet recording apparatus 72 and the inkjet recording apparatus. The ink jet recording apparatus shown in FIG. 18 is similar to the ink jet recording apparatus shown in FIG.
Has a protrusion 258 '. The protrusion 258 'includes an elastic wave generation means 260'. The gelling material 280 ′ is engaged with the convex portion 258 ′ to
74b. According to the ink cartridge 272 shown in FIG. 18, when the remaining amount of ink decreases and a part of the elastic wave irradiation unit 260 'is irradiated from the liquid surface, the elastic wave generated by the elastic wave generation unit 260' The arrival time and acoustic impedance of the reflected wave to the elastic wave generation means 260 'continuously change in accordance with the change Δh2 in the liquid level. Δh2 represents a difference in height between the upper end and the lower end of the gelling material 280 ′. Therefore, the process from the ink near-end state to the ink end can be accurately detected by detecting the arrival time of the reflected wave to the elastic wave generating means 260 'or the degree of change in the acoustic impedance.

In the above embodiment, the container 27
4 has been described by taking an example of an ink cartridge of a type that directly stores ink. In another embodiment, the container 274
The elastic wave generating means 26 is provided in an ink cartridge of a type in which a porous elastic body is loaded into the ink cartridge and the porous elastic body is impregnated with ink.
0 may be applied. Further, in the above embodiment,
When detecting the remaining amount of the ink based on the reflected wave at the liquid surface, the same elastic wave generating means 260 and 260 'transmitted and received the elastic wave. The present invention is not limited to this. For example, as another embodiment, different elastic wave generating means 260 may be used for transmitting and receiving elastic waves.

FIG. 19 shows another embodiment of the ink cartridge 272 shown in FIG. The ink cartridge 272 attaches the plate member 316 to the float 318 and covers the ink liquid surface, thereby increasing the intensity of the reflected wave from the ink liquid surface. The plate material 316 has a high acoustic impedance,
Further, it is preferable to be formed of a material having ink resistance, for example, ceramic or the like.

FIGS. 20 and 21 show details and an equivalent circuit of an actuator 106 which is an embodiment of the piezoelectric device. The actuator referred to here is used in a method of detecting at least a change in acoustic impedance and detecting a consumption state of the liquid in the liquid container. In particular, it is used in a method of detecting a resonance frequency by residual vibration to detect at least a change in acoustic impedance to detect a consumption state of a liquid in a liquid container. FIG. 20A is an enlarged plan view of the actuator 106. FIG. 20 (B)
Shows a BB cross section of the actuator 106. FIG.
(C) shows a CC cross section of the actuator 106.
FIGS. 21A and 21B show an equivalent circuit of the actuator 106. FIGS. 21C and 21D show the periphery including the actuator 106 and the equivalent circuit thereof when the ink cartridge is filled with ink, respectively, and FIGS. 21E and 21F () Shows the periphery including the actuator 106 when there is no ink in the ink cartridge and its equivalent circuit.

The actuator 106 includes a substrate 178 having a circular opening 161 at substantially the center, a vibration plate 176 provided on one surface (hereinafter referred to as a surface) of the substrate 178 so as to cover the opening 161, A piezoelectric layer 160 disposed on the side of the surface of the plate 176; and upper and lower electrodes 164 and 166 sandwiching the piezoelectric layer 160 from both sides.
And upper electrode terminal 1 electrically coupled to upper electrode 164
68, a lower electrode terminal 170 electrically coupled to the lower electrode 166, an upper electrode 164 and an upper electrode terminal 168.
And an auxiliary electrode 172 electrically connected therebetween. Each of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 has a circular portion as a main part. Each circular portion of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 forms a piezoelectric element.

The vibration plate 176 is formed on the surface of the substrate 178 so as to cover the opening 161. Cavity 162
Is the portion of the diaphragm 176 facing the opening 161 and the substrate 17
8 is formed by the opening 161 on the surface. Substrate 17
The surface opposite to the piezoelectric element 8 (hereinafter referred to as the back surface) faces the liquid container side, and the cavity 162 is configured to be in contact with the liquid. The vibration plate 176 is attached to the substrate 178 in a liquid-tight manner so that even if the liquid enters the cavity 162, the liquid does not leak to the surface side of the substrate 178.

The lower electrode 166 is located on the surface of the diaphragm 176, that is, on the surface opposite to the liquid container.
It is attached so that the center of the circular portion which is the main part of 66 and the center of the opening 161 substantially coincide with each other. The area of the circular portion of the lower electrode 166 is set to be smaller than the area of the opening 161. On the other hand, the lower electrode 1
The piezoelectric layer 160 is formed on the surface side of the substrate 66 such that the center of the circular portion substantially coincides with the center of the opening 161. The area of the circular portion of the piezoelectric layer 160 is
, And larger than the area of the circular portion of the lower electrode 166.

On the other hand, on the front surface side of the piezoelectric layer 160, an upper electrode 164 is provided at the center of the circular portion which is the main portion thereof and the opening 1
61 are formed so as to substantially coincide with the center. The area of the circular portion of the upper electrode 164 is smaller than the area of the opening 161 and the circular portion of the piezoelectric layer 160, and the lower electrode 1
The area is set to be larger than the area of the circular portion 66.

Therefore, the main part of the piezoelectric layer 160 is sandwiched by the main part of the upper electrode 164 and the main part of the lower electrode 166 from the front side and the back side, respectively. The deformation driving can be performed effectively. The circular portions that are the main parts of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form the piezoelectric element of the actuator 106. As described above, the piezoelectric element is in contact with the vibration plate 176. Of the circular portion of the upper electrode 164, the circular portion of the piezoelectric layer 160, the circular portion of the lower electrode 166, and the opening 161, the opening 161 has the largest area. With this structure, the vibration area of the vibration plate 176 that actually vibrates is determined by the opening 161. The circular portion of the upper electrode 164, the circular portion of the piezoelectric layer 160, and the lower electrode 16
Since the circular portion 6 has a smaller area than the opening 161, the diaphragm 176 is more likely to vibrate. Further, the piezoelectric layer 16
Of the circular portion of the lower electrode 166 and the circular portion of the upper electrode 164 electrically connected to 0, the circular portion of the lower electrode 166 is smaller. Therefore, the circular portion of the lower terminal 166 determines a portion of the piezoelectric layer 160 where the piezoelectric effect occurs.

The upper electrode terminal 168 is formed on the surface of the diaphragm 176 so as to be electrically connected to the upper electrode 164 via the auxiliary electrode 172. On the other hand, the lower electrode terminal 17
0 is formed on the surface side of diaphragm 176 so as to be electrically connected to lower electrode 166. Since the upper electrode 164 is formed on the surface side of the piezoelectric layer 160, the upper electrode terminal 16
8, it is necessary to have a step equal to the sum of the thickness of the piezoelectric layer 160 and the thickness of the lower electrode 166. It is difficult to form this step only with the upper electrode 164, and even if possible, the connection between the upper electrode 164 and the upper electrode terminal 168 is weakened, and there is a risk of disconnection. Therefore, the upper electrode 164 and the upper electrode terminal 16 are formed by using the auxiliary electrode 172 as an auxiliary member.
8 is connected. By doing so, both the piezoelectric layer 160 and the upper electrode 164 have a structure supported by the auxiliary electrode 172, so that a desired mechanical strength can be obtained, and the connection between the upper electrode 164 and the upper electrode terminal 168 is ensured. It becomes possible to.

Note that the piezoelectric element and the vibration area of the vibration plate 176 facing the piezoelectric element correspond to the actuator 106.
Is a vibrating part that actually vibrates. Further, the members included in the actuator 106 are preferably integrally formed by firing each other. By forming the actuator 106 integrally, handling of the actuator 106 becomes easy. Further, the vibration characteristics are improved by increasing the strength of the substrate 178. That is, by increasing the strength of the substrate 178, only the vibrating portion of the actuator 106 vibrates, and portions of the actuator 106 other than the vibrating portion do not vibrate. Also, in order to prevent portions other than the vibrating portion of the actuator 106 from vibrating, it is possible to increase the strength of the substrate 178 while making the piezoelectric element of the actuator 106 thinner and smaller and the diaphragm 176 thinner.

As a material of the piezoelectric layer 160, it is preferable to use lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), or a lead-free piezoelectric film not using lead. Alternatively, it is preferable to use alumina. It is preferable that the same material as the substrate 178 be used for the diaphragm 176. For the upper electrode 164, the lower electrode 166, the upper electrode terminal 168, and the lower electrode terminal 170, a conductive material such as a metal such as gold, silver, copper, platinum, aluminum, or nickel can be used.

The actuator 106 configured as described above can be applied to a container for storing a liquid. For example, it can be mounted on an ink cartridge or ink tank used for an ink jet recording apparatus, or a container containing a cleaning liquid for cleaning a recording head.

The actuator 106 shown in FIG. 20 and FIG.
62 is attached so as to be in contact with the liquid contained in the liquid container. When the liquid is sufficiently stored in the liquid container, the inside and outside of the cavity 162 are filled with the liquid. On the other hand, the liquid in the liquid container is consumed,
When the liquid level drops below the mounting position of the actuator,
No liquid exists in the cavity 162, or the liquid remains only in the cavity 162 and a gas exists outside thereof. The actuator 106 is
At least a difference in acoustic impedance due to the change in the state is detected. Thereby, the actuator 106 can detect whether the liquid container is in a state where the liquid is sufficiently stored or whether the liquid container is in a state where a certain amount or more of the liquid is consumed. Further, the actuator 106 can also detect the type of liquid in the liquid container.

Here, the principle of liquid level detection by the actuator will be described.

To detect a change in the acoustic impedance of the medium, the impedance characteristics or admittance characteristics of the medium are measured. When measuring the impedance characteristic or the admittance characteristic, for example, a transmission circuit can be used. The transmission circuit applies a constant voltage to the medium, changes the frequency, and measures the current flowing through the medium. Alternatively, the transmission circuit supplies a constant current to the medium, changes the frequency, and measures the voltage applied to the medium. A change in the current value or voltage value measured by the transmission circuit indicates a change in acoustic impedance. Further, a change in the frequency fm at which the current value or the voltage value becomes maximum or minimum also indicates a change in acoustic impedance.

Apart from the method described above, the actuator
A change in the acoustic impedance of the liquid can be detected using only a change in the resonance frequency. As a method using the change in acoustic impedance of the liquid, when using a method of detecting a resonance frequency by measuring a back electromotive force generated by residual vibration remaining in the vibrating portion after the vibrating portion of the actuator vibrates, for example, A piezoelectric element can be used. A piezoelectric element is an element that generates a back electromotive force due to residual vibration remaining in a vibrating part of an actuator, and the magnitude of the back electromotive force changes according to the amplitude of the vibrating part of the actuator. Therefore, the larger the amplitude of the vibrating part of the actuator, the easier it is to detect. Further, the cycle at which the magnitude of the back electromotive force changes depends on the frequency of the residual vibration in the vibrating portion of the actuator. Therefore, the frequency of the vibrating part of the actuator corresponds to the frequency of the back electromotive force. Here, the resonance frequency refers to a frequency in a resonance state between the vibrating portion of the actuator and the medium in contact with the vibrating portion.

In order to obtain the resonance frequency fs, the waveform obtained by the back electromotive force measurement when the vibrating section and the medium are in a resonance state is subjected to Fourier transform. The vibration of the actuator is not only deformed in one direction but is accompanied by various deformations such as bending and elongation, and thus has various frequencies including the resonance frequency fs. Therefore, the resonance frequency fs is determined by Fourier-transforming the waveform of the back electromotive force when the piezoelectric element and the medium are in a resonance state, and specifying the most dominant frequency component.

The frequency fm is the frequency when the admittance of the medium is maximum or the impedance is minimum. Assuming that the resonance frequency is fs, the frequency fm is equal to the resonance frequency fs due to dielectric loss or mechanical loss of the medium.
Causes a slight error. However, deriving the resonance frequency fs from the actually measured frequency fm is troublesome, and therefore, generally, the frequency fm is used instead of the resonance frequency. Here, by inputting the output of the actuator 106 to the transmission circuit, the actuator 106 can detect at least the acoustic impedance.

The frequency fm is measured by measuring the impedance characteristic or the admittance characteristic of the medium, and the resonance frequency fs is measured by measuring the back electromotive force generated by the residual vibration in the vibrating part of the actuator. It has been proved by experiments that there is almost no difference in the resonance frequencies to be obtained.

The vibration area of the actuator 106 is a part of the vibration plate 176 that forms the cavity 162 determined by the opening 161. When the liquid is sufficiently contained in the liquid container, the cavity 162 is filled with the liquid, and the vibrating region comes into contact with the liquid in the liquid container. On the other hand, if there is not enough liquid in the liquid container, the vibrating region will be in contact with the liquid remaining in the cavity in the liquid container, or will not be in contact with the liquid, but will be in contact with gas or vacuum.

The actuator 106 of the present invention is provided with the cavity 162 so that the liquid in the liquid container can be designed to remain in the vibration region of the actuator 106. The reason is as follows.

Depending on the mounting position and the mounting angle of the actuator on the liquid container, the liquid adheres to the vibration area of the actuator even though the liquid level in the liquid container is below the mounting position of the actuator. In some cases. When the actuator detects the presence / absence of the liquid only by the presence / absence of the liquid in the vibration region, the liquid attached to the vibration region of the actuator prevents accurate detection of the presence / absence of the liquid. For example, when the liquid level is below the mounting position of the actuator, the liquid container swings due to the reciprocating movement of the carriage or the like, causing the liquid to wave,
If the droplets adhere to the vibrating area, the actuator incorrectly determines that there is sufficient liquid in the liquid container. Therefore, conversely, even if the liquid remains there, by positively providing a cavity designed to accurately detect the presence or absence of the liquid, the liquid container rocked and the liquid surface wavy However, malfunction of the actuator can be prevented. As described above, malfunction can be prevented by using the actuator having the cavity.

As shown in FIG. 21 (E), the case where there is no liquid in the liquid container and the liquid in the liquid container remains in the cavity 162 of the actuator 106 is defined as the threshold for the presence or absence of the liquid. That is, when there is no liquid around the cavity 162 and the amount of liquid in the cavity is smaller than this threshold, it is determined that there is no ink. When there is liquid around the cavity 162 and there is more liquid than this threshold, there is ink. to decide. For example, when the actuator 106 is mounted on the side wall of the liquid container, it is determined that there is no ink when the liquid in the liquid container is below the mounting position of the actuator, and the liquid in the liquid container is positioned above the mounting position of the actuator. If there is, it is determined that there is ink. By setting the threshold value in this manner, it is determined that there is no ink even when the ink in the cavity has dried and the ink has run out. Since the threshold value is not exceeded even if the ink adheres to the cavity, it can be determined that there is no ink.

The operation and principle of detecting the state of the liquid in the liquid container from the resonance frequency of the medium and the vibrating portion of the actuator 106 by measuring the back electromotive force will be described with reference to FIGS. 20 and 21. In the actuator 106, a voltage is applied to the upper electrode 164 and the lower electrode 166 via the upper electrode terminal 168 and the lower electrode terminal 170, respectively. Of the piezoelectric layer 160,
An electric field is generated in a portion sandwiched between the upper electrode 164 and the lower electrode 166. The piezoelectric layer 160 is deformed by the electric field. When the piezoelectric layer 160 is deformed, the diaphragm 1
The vibration area of 76 vibrates flexibly. Piezoelectric layer 160
For a while after the deformation, the flexural vibration remains in the vibrating portion of the actuator 106.

The residual vibration is free vibration between the vibration part of the actuator 106 and the medium. Therefore, by making the voltage applied to the piezoelectric layer 160 a pulse waveform or a rectangular wave, a resonance state between the vibrating portion and the medium can be easily obtained after the voltage is applied. The residual vibration is
In order to vibrate the vibrating portion 06, the piezoelectric layer 160 is also deformed. Therefore, the piezoelectric layer 160 generates a back electromotive force. The back electromotive force is detected via the upper electrode 164, the lower electrode 166, the upper electrode terminal 168, and the lower electrode terminal 170. Since the resonance frequency can be specified by the detected back electromotive force, the state of the liquid in the liquid container can be detected.

In general, the resonance frequency fs is expressed by fs = 1 / (2 * π * (M * Cact) ^1/2 ) (Equation 1). Here, M is the inertance Mact of the vibrating part.
And the additional inertance M ′. Cact is the compliance of the vibrating part.

FIG. 20C is a sectional view of the actuator 106 in this embodiment when no ink remains in the cavity. FIG. 21 (A) and FIG. 21 (B)
Is an equivalent circuit of the vibrating section of the actuator 106 and the cavity 162 when no ink remains in the cavity.

Mact is obtained by dividing the product of the thickness of the vibrating portion and the density of the vibrating portion by the area of the vibrating portion. More specifically, as shown in FIG. 21A, Mact = Mpzt + Melectrode1 + Melectrode2 + Mvib (formula 2) is expressed as Here, Mpzt is the product of the thickness of the piezoelectric layer 160 in the vibrating portion and the density of the piezoelectric layer 160,
It is divided by the area of 0. Melectrode1 is obtained by dividing the product of the thickness of the upper electrode 164 and the density of the upper electrode 164 in the vibrating section by the area of the upper electrode 164. M
electrode2 is the product of the product of the thickness of the lower electrode 166 and the density of the lower electrode 166 in the vibrating section divided by the area of the lower electrode 166. Mvib is the diaphragm 1 in the vibrating section.
The product of the thickness of the diaphragm 76 and the density of the diaphragm 176 is
Of the vibration region. However, Mact
In this embodiment, the piezoelectric layer 160 and the piezoelectric layer 160 can be calculated from the thickness, density, and area of the entire vibrating portion.
Although the respective areas of the upper electrode 164, the lower electrode 166, and the vibration region of the diaphragm 176 have the magnitude relationship as described above, it is preferable that the difference between the areas is small. In the present embodiment, it is preferable that portions of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 other than the circular portion, which are main portions thereof, are so small as to be negligible with respect to the main portion. Therefore, in the actuator 106, Mact is the upper electrode 164,
This is the sum of the inertances of the lower electrode 166, the piezoelectric layer 160, and the vibration area of the vibration plate 176. The compliance Cact is a compliance of a portion formed by the vibration region of the upper electrode 164, the lower electrode 166, the piezoelectric layer 160, and the vibration plate 176.

It should be noted that FIGS. 21A, 21B and 21
(D) and FIG. 21 (F) show equivalent circuits of the vibrating part of the actuator 106 and the cavity 162. In these equivalent circuits, Cact indicates compliance of the vibrating part of the actuator 106. Cpzt, Celectrode
1, Celectrode2 and Cvib indicate compliance of the piezoelectric layer 160, the upper electrode 164, the lower electrode 166, and the diaphragm 176 in the vibrating portion, respectively. Cact is represented by the following equation 3.

1 / Cact = (1 / Cpzt) + (1 / Celectrode1) + (1 / Celectrode2) + (1 / Cvi b) (Equation 3) From Equations 2 and 3, FIG. 21 (B).

The compliance Cact represents a volume that can receive a medium by deformation when pressure is applied to a unit area of the vibrating part. Further, the compliance Cact may be said to indicate the ease of deformation.

FIG. 21C is a cross-sectional view of the actuator 106 when the liquid is sufficiently contained in the liquid container and the periphery of the vibration region of the actuator 106 is filled with the liquid. M′max in FIG. 21C represents the maximum value of the additional inertance when the liquid is sufficiently stored in the liquid container and the liquid is filled around the vibration region of the actuator 106. M'max is

M′max = (π * ρ / (2 * k ³ )) * (2 * (2 * k * a) ³ / (3 * π)) / (π * a ² ) ² (Equation 4) (A is the radius of the vibrating part, ρ is the density of the medium, and k is the wave number.)

Is represented by Expression 4 holds when the vibration region of the actuator 106 is a circle having a radius a. The additional inertance M ′ is a quantity indicating that the mass of the vibrating part is apparently increased by the action of the medium near the vibrating part. As can be seen from Equation 4, M′max
Varies greatly depending on the radius a of the vibrating portion and the density ρ of the medium.

The wave number k is as follows: k = 2 * π * fact / c (Equation 5) (fact is the resonance frequency of the vibrating part when the liquid is not touching. C is the speed of sound propagating in the medium. .)

Is represented by

FIG. 21D shows the vibrating portion and the cavity 162 of the actuator 106 in the case of FIG. 21C in which the liquid is sufficiently contained in the liquid container and the liquid is filled around the vibrating region of the actuator 106. Is shown.

FIG. 21E shows the state of the actuator 106 when the liquid in the liquid container is consumed and there is no liquid around the vibrating region of the actuator 106 but the liquid remains in the cavity 162 of the actuator 106. FIG. Equation 4 is an equation representing the maximum inertance M′max determined from the density ρ of the ink when the liquid container is filled with the liquid, for example. On the other hand, when the liquid in the liquid container is consumed and the liquid around the vibration region of the actuator 106 becomes gas or vacuum while the liquid remains in the cavity 162,

M ′ = ρ * t / S (Equation 6) t is the thickness of the medium involved in the vibration. S
Is the area of the vibration region of the actuator 106. When this vibration region is a circle having a radius a, S = π * a ² . Therefore, the additional inertance M ′ follows Expression 4 when the liquid is sufficiently stored in the liquid container and the liquid is filled around the vibration region of the actuator 106. On the other hand, when the liquid is consumed and the liquid around the vibration region of the actuator 106 becomes gas or vacuum while the liquid remains in the cavity 162, Equation 6 is followed.

Here, as shown in FIG. 21 (E), the liquid in the liquid container is consumed, and there is no liquid around the vibration region of the actuator 106, but the liquid remains in the cavity 162 of the actuator 106. In this case, the additional inertance M ′ is M′cav for convenience, and is distinguished from the additional inertance M′max when the liquid is filled around the vibration region of the actuator 106.

FIG. 21F shows that the liquid in the liquid container is consumed and no liquid exists around the vibration region of the actuator 106, but the liquid remains in the cavity 162 of the actuator 106. 5 shows an equivalent circuit of the vibrating section of the actuator 106 and the cavity 162 in the case of FIG.

Here, the parameters related to the state of the medium are the density ρ of the medium and the thickness t of the medium in Equation (6). When the liquid is sufficiently stored in the liquid container, the liquid comes into contact with the vibrating portion of the actuator 106. When the liquid is not sufficiently stored in the liquid container, the liquid remains in the cavity or Alternatively, gas or vacuum comes into contact with the vibrating portion of the actuator 106. The liquid around the actuator 106 is consumed, and FIG.
If the additional inertance in the process of shifting from M′max to M′cav in FIG. 21 (E) is M ′ var, the thickness t of the medium changes depending on the state of the liquid contained in the liquid container. M′var changes, and the resonance frequency fs also changes. Therefore, by specifying the resonance frequency fs, the presence or absence of the liquid in the liquid container can be detected. Here, as shown in FIG.
= D, M′cav is expressed using Equation 6, and Equation 6
Substituting the cavity depth d for t

M′cav = ρ * d / S (Equation 7)

Further, even if the mediums are liquids of different types, the added inertance M 'changes and the resonance frequency fs changes because the density ρ differs depending on the composition. Therefore, the type of liquid can be detected by specifying the resonance frequency fs. When only one of ink and air comes into contact with the vibrating portion of the actuator 106 and does not coexist, the difference in M ′ can be detected even by calculation using Expression 4.

FIG. 22A is a graph showing the relationship between the amount of ink in the ink tank and the ink and the resonance frequency fs of the vibrating section. Here, an ink will be described as an example of the liquid. The vertical axis indicates the resonance frequency fs, and the horizontal axis indicates the ink amount. When the ink composition is constant, the resonance frequency fs increases with a decrease in the remaining amount of ink.

When the ink is sufficiently contained in the ink container and the ink is filled around the vibration region of the actuator 106, the maximum additional inertance M′max
Is the value represented by Equation 4. On the other hand, when the ink is consumed and the ink is not filled around the vibration region of the actuator 106 while the liquid remains in the cavity 162, the additional inertance M′var is calculated based on the thickness t of the medium. It is calculated by Since t in Expression 6 is the thickness of the medium involved in the vibration, the actuator 1
By making d (see FIG. 20B) of the cavity 162 of No. 06 small, that is, by making the substrate 178 sufficiently thin,
A process in which the ink is gradually consumed can also be detected (see FIG. 21C). Here, tink is the thickness of the ink relating to the vibration, and tink-max is tink at M′max. For example, the actuator 106 is provided on the bottom surface of the ink cartridge substantially horizontally with respect to the ink level. When the ink is consumed and the liquid level of the ink reaches the height of tink-max or less from the actuator 106, M′var gradually changes according to Equation 6, and the resonance frequency fs gradually changes according to Equation 1. Therefore, as long as the ink level is within the range of t, the actuator 106 can gradually detect the ink consumption state.

Further, by increasing or lengthening the vibration area of the actuator 106 and arranging it vertically, according to the position of the liquid surface due to ink consumption, S
Changes. Therefore, the actuator 106 can also detect a process in which the ink is gradually consumed. For example, the actuator 10 is provided on the side wall of the ink cartridge.
6 is arranged substantially perpendicular to the ink level. When the ink is consumed and the liquid level of the ink reaches the vibration region of the actuator 106, the additional inertance M ′ decreases as the water level decreases, so that the resonance frequency fs gradually increases according to Equation 1. Therefore, the liquid level of the ink is
2 within the range of the diameter 2a (see FIG. 21C).
The actuator 106 can gradually detect the ink consumption state.

A curve X in FIG.
6 shows the relationship between the amount of ink contained in the ink tank and the ink and the resonance frequency fs of the vibrating part when the cavity 162 of the actuator 06 is made sufficiently shallow or when the vibration region of the actuator 106 is made sufficiently large or long. ing. It can be understood that as the amount of ink in the ink tank decreases, the resonance frequency fs of the ink and the vibrating part gradually changes.

More specifically, the case where the process in which the ink is gradually consumed can be detected means that both the liquid and the gas having different densities exist around the vibration region of the actuator 106, and This is the case related to vibration. As the ink is gradually consumed,
In the medium related to the vibration around the vibration region of the actuator 106, the liquid increases while the gas increases.
For example, in a case where the actuator 106 is disposed horizontally with respect to the ink level, and when tink is smaller than tink-max, the medium involved in the vibration of the actuator 106 includes both ink and gas. Therefore, assuming that the area S of the vibration region of the actuator 106 is:
When the state of M'max or less is represented by the added mass of ink and gas,

M ′ = M′air + M′ink = ρair * tair / S + ρink * tink / S (Equation 8) Here, M'air is the inertance of air, and M'ink is the inertance of ink. ρair is the density of air, and ρink is the density of the ink. tair is the thickness of the air involved in the vibration, and tink is the thickness of the ink involved in the vibration. As the liquid decreases and the gas increases in the medium related to the vibration around the vibration region of the actuator 106, tair increases when the actuator 106 is arranged substantially horizontally with respect to the ink level, tink decreases. Thereby,
M'var gradually decreases, and the resonance frequency gradually increases. Therefore, the amount of ink remaining in the ink tank or the amount of consumed ink can be detected. It should be noted that the reason why only the density of the liquid is used in Equation 7 is that it is assumed that the density of the air is negligibly small compared to the density of the liquid.

In the case where the actuator 106 is disposed substantially perpendicular to the ink surface, among the vibration regions of the actuator 106, the region related to the vibration of the actuator 106 is the region of the ink only, The medium involved is considered as an equivalent circuit (not shown) in parallel with the region of the gas. Actuator 10
The medium relating to the vibration of No. 6 has the area of the ink-only area as S
Assuming that the area of the region where only the medium relating to the vibration of the actuator 106 is gas is Sair,

1 / M ′ = 1 / M′air + 1 / M′ink = Sair / (ρair * tair) + Sink / (ρink * tink) (Equation 9)

Equation 9 is applied when ink is not held in the cavity of the actuator 106. The case where the ink is held in the cavity of the actuator 106 can be calculated by Expressions 7, 8, and 9.

On the other hand, when the substrate 178 is thick, that is, when the depth d of the cavity 162 is deep and d is relatively close to the medium thickness tink-max, or when the vibration region is very large compared to the height of the liquid container. When a small actuator is used, the fact that the ink level is higher or lower than the actuator mounting position is actually detected rather than detecting the process of gradually decreasing the ink. In other words, the presence or absence of ink in the vibration region of the actuator is detected. For example, a curve Y in FIG. 22A shows a relationship between the amount of ink in the ink tank and the ink and the resonance frequency fs of the vibrating part in the case of a small circular vibration region.
A state is shown in which the resonance frequency fs of the ink and the vibrating part changes drastically between the ink amounts Q before and after the liquid level of the ink in the ink tank passes through the mounting position of the actuator. From this, it is possible to detect whether a predetermined amount of ink remains in the ink tank.

FIG. 22B shows the relationship between the ink density and the ink and the resonance frequency fs of the vibrating section in the curve Y in FIG. 22A. Ink is given as an example of the liquid. As shown in FIG. 22B, when the ink density increases, the additional inertance increases, so that the resonance frequency fs
Decrease. That is, the resonance frequency fs differs depending on the type of ink. Therefore, by measuring the resonance frequency fs, it is possible to confirm whether inks having different densities are mixed when the ink is refilled.

That is, it is possible to identify ink tanks containing different types of ink.

Subsequently, when the size and shape of the cavity are set so that the liquid remains in the cavity 162 of the actuator 106 even when the liquid in the liquid container is empty, the state of the liquid is accurately detected. The possible conditions will be described in detail. If the actuator 106 can detect the state of the liquid when the cavity 162 is filled with the liquid,
Even when the cavity 162 is not filled with the liquid, the state of the liquid can be detected.

The resonance frequency fs is a function of the inertance M. The inertance M is the inertance Mac of the vibrating part.
It is the sum of t and the additional inertance M '. Here, the additional inertance M ′ is related to the state of the liquid. The additional inertance M ′ is an amount indicating that the mass of the vibrating part is apparently increased by the action of the medium near the vibrating part. That is, it means an increase in the mass of the vibrating section due to apparent absorption of the medium by the vibration of the vibrating section.

Therefore, when M'cav is larger than M'max in Equation 4, all the apparently absorbing media are liquids remaining in the cavity 162. Therefore, it is the same as the state where the liquid is filled in the liquid container. In this case, since M ′ does not change, the resonance frequency fs does not change. Therefore, the actuator 106 cannot detect the state of the liquid in the liquid container.

On the other hand, when M'cav is smaller than M'max in Equation 4, the medium apparently absorbed is the liquid remaining in the cavity 162 and the gas or vacuum in the liquid container. At this time, unlike the state where the liquid is filled in the liquid container, M ′ changes, so that the resonance frequency fs changes. Therefore, the actuator 106
The state of the liquid in the liquid container can be detected.

That is, when the liquid in the liquid container is empty and the liquid remains in the cavity 162 of the actuator 106, the condition under which the actuator 106 can accurately detect the liquid state is that M'cav is M'cav. It is smaller than max. The condition M′max> M′cav at which the actuator 106 can accurately detect the state of the liquid is defined as the cavity 1
Regardless of the shape of 62.

Here, M'cav is the mass of the liquid having a volume substantially equal to the volume of the cavity 162. Therefore,
From the inequality M′max> M′cav, the actuator 106
The conditions under which the liquid state can be accurately detected are cavity 1
It can be expressed as a condition of a capacity of 62. For example, let a be the radius of the opening 161 of the circular cavity 162,
And the depth of the cavity 162 is d,

M′max> ρ * d / πa ² (Equation 10). Expanding Equation 10 gives

The condition of a / d> 3 * π / 8 (Equation 11) is required. Equations 10 and 11 are
This is true only when the shape of the bitty 162 is circular. Round
Πa in equation 10 using the equation of M′max ^TwoTo
By calculating the area of the cavity, the width of the cavity and
The relationship between dimensions such as length and depth can be derived.

Therefore, the radius of the opening 161 satisfying the equation (11)
a and cavity 1 at depth d of cavity 162
The actuator 106 having 62 can detect the state of the liquid without malfunction even if the liquid in the liquid container is empty and the liquid remains in the cavity 162.

Since the additional inertance M 'also affects the acoustic impedance characteristics, it can be said that the method of measuring the back electromotive force generated in the actuator 106 due to the residual vibration detects at least a change in the acoustic impedance.

Further, according to the present embodiment, the back electromotive force generated in the actuator 106 due to the vibration generated by the actuator 106 and subsequent residual vibration is measured. However, it is not always necessary for the vibrating section of the actuator 106 to vibrate the liquid by its own vibration due to the drive voltage. That is, even if the vibrating part does not oscillate by itself, it vibrates together with a certain range of liquid in contact with the vibrating part, whereby the piezoelectric layer 160 bends and deforms. This residual vibration generates a back electromotive force voltage in the piezoelectric layer 160, and the upper electrode 164
And the lower electromotive force voltage to lower electrode 166.
The state of the medium may be detected by utilizing this phenomenon. For example, in an ink jet recording apparatus, even if the state of the ink tank or the ink inside the ink tank is detected by using the vibration around the vibration part of the actuator generated by the vibration due to the reciprocating movement of the carriage due to the scan of the print head during printing. Good.

FIGS. 23A and 23B show the actuator 1 after the actuator 106 is vibrated.
6 shows a waveform of the residual vibration and a method of measuring the residual vibration.
Up and down of the ink level at the mounting position level of the actuator 106 in the ink cartridge can be detected by a change in the frequency or amplitude of the residual vibration after the actuator 106 oscillates. 23A and 23B, the vertical axis represents the actuator 106.
Represents the voltage of the back electromotive force generated by the residual vibration, and the horizontal axis represents time. Due to the residual vibration of the actuator 106, a voltage analog signal waveform is generated as shown in FIGS. 23 (A) and 23 (B). Next, the analog signal is converted into a digital numerical value corresponding to the frequency of the signal.

In the example shown in FIGS. 23A and 23B, the presence or absence of ink is determined by measuring the time during which four pulses from the fourth pulse to the eighth pulse of the analog signal are generated. To detect.

More specifically, the number of times the actuator 106 oscillates and crosses a predetermined reference voltage from a low voltage side to a high voltage side after oscillation is counted. A digital signal between 4 and 8 counts is defined as High,
The time from 4 counts to 8 counts is measured by a predetermined clock pulse.

FIG. 23A shows a waveform when the ink level is higher than the mounting position level of the actuator 106. On the other hand, FIG. 23B shows a waveform when there is no ink at the mounting position level of the actuator 106. When FIG. 23A is compared with FIG. 23B, FIG.
It can be seen that 3 (A) has a longer time from 4 counts to 8 counts than FIG. 23 (B). In other words, the time from 4 counts to 8 counts differs depending on the presence or absence of ink. The ink consumption state can be detected using the difference in the time. The counting from the fourth count of the analog waveform is for starting the measurement after the vibration of the actuator 106 is stabilized. Starting from the fourth count is merely an example, and counting from an arbitrary count may be performed. Here, signals from the 4th to 8th counts are detected, and the time from the 4th to 8th counts is measured by a predetermined clock pulse.
Thereby, the resonance frequency is obtained. The clock pulse is preferably a clock pulse equal to a clock for controlling a semiconductor memory device or the like attached to the ink cartridge. It is not necessary to measure the time up to the eighth count, and the time may be counted up to an arbitrary count. In FIG. 23, the time from the fourth count to the eighth count is measured, but the time within a different count interval may be detected according to the circuit configuration for detecting the frequency.

For example, when the ink quality is stable and the fluctuation of the peak amplitude is small, the resonance frequency is obtained by detecting the time from the fourth count to the sixth count in order to increase the detection speed. You may. When the ink quality is unstable and the pulse amplitude fluctuates greatly, the time from the fourth count to the twelfth count may be detected in order to accurately detect the residual vibration.

As another embodiment, the wave number of the voltage waveform of the back electromotive force within a predetermined period may be counted (not shown). The resonance frequency can also be obtained by this method. More specifically, after the actuator 106 oscillates, the digital signal is set to High only for a predetermined period, and the number of times the predetermined reference voltage crosses the low voltage side to the high voltage side is counted. By measuring the count, the presence or absence of ink can be detected.

Further, as can be seen by comparing FIGS. 23A and 23B, the back electromotive force differs between when the ink is filled in the ink cartridge and when the ink is not in the ink cartridge. Waveform amplitude is different. Therefore, the consumption state of the ink in the ink cartridge may be detected by measuring the amplitude of the back electromotive force waveform without obtaining the resonance frequency. More specifically, for example, a reference voltage is set between the top of the back electromotive force waveform of FIG. 23A and the top of the back electromotive force waveform of FIG. 23B. After the actuator 106 oscillates, the digital signal is set to High for a predetermined time, and when the back electromotive force crosses the reference voltage, it is determined that there is no ink. If the back electromotive force waveform does not cross the reference voltage, it is determined that there is ink.

FIG. 24 shows a method of manufacturing the actuator 106. A plurality of actuators 106 (four in the example of FIG. 24) are formed integrally. The actuator 106 shown in FIG. 25 is manufactured by cutting the integrally molded product of the plurality of actuators shown in FIG. When each of the piezoelectric elements of the plurality of integrally formed actuators 106 shown in FIG. 24 has a circular shape, the integrally formed product is cut at each of the actuators 106 to obtain a structure shown in FIG.
Can be manufactured.
By integrally forming the plurality of actuators 106, the plurality of actuators 106 can be manufactured efficiently at the same time, and handling during transportation becomes easy.

The actuator 106 includes a thin plate or a vibration plate 176, a substrate 178, an elastic wave generating means or a piezoelectric
4, a terminal forming member or upper electrode terminal 168 and a terminal forming member or lower electrode terminal 170; Piezoelectric element 17
4 includes a piezoelectric diaphragm or piezoelectric layer 160, an upper or upper electrode 164, and a lower or lower electrode 166. A vibration plate 176 is formed on the upper surface of the substrate 178, and the vibration plate 17
6, a lower electrode 166 is formed. On the upper surface of the lower electrode 166, a piezoelectric layer 160 is formed.
An upper electrode 164 is formed on the upper surface of 60. Therefore, the main part of the piezoelectric layer 160 is formed so as to be sandwiched from above and below by the main part of the upper electrode 164 and the main part of the lower electrode 166.

A plurality (4 in the example of FIG. 24)
) Of piezoelectric elements 174 are formed. Diaphragm 176
The lower electrode 166 is formed on the surface of the piezoelectric layer 160, the piezoelectric layer 160 is formed on the surface of the lower electrode 166, and the upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. An upper electrode terminal 168 and a lower electrode terminal 170 are formed at ends of the upper electrode 164 and the lower electrode 166. Four actuators 106
Are cut separately and used individually.

FIG. 25 shows a cross section of a part of an actuator 106 having a rectangular piezoelectric element.

FIG. 26 shows an overall cross section of the actuator 106 shown in FIG. Piezoelectric element 17 on substrate 178
A through hole 178a is formed on the surface facing 4. The through hole 178a is sealed by the diaphragm 176. The vibration plate 176 is formed of a material having electrical insulation such as alumina or zirconia and capable of being elastically deformed. A piezoelectric element 174 is formed on the vibration plate 176 so as to face the through hole 178a. The lower electrode 166 is formed on the surface of the diaphragm 176 so as to extend in one direction from the region of the through hole 178a, to the left in FIG. The upper electrode 164 is formed on the surface of the piezoelectric layer 160 so as to extend from the region of the through hole 178a in the direction opposite to the lower electrode, and to the right in FIG. Upper electrode terminal 16
8 and the lower electrode terminal 170 are connected to the auxiliary electrode 172, respectively.
And on the upper surface of the lower electrode 166. The lower electrode terminal 170 is in electrical contact with the lower electrode 166, and the upper electrode terminal 168 is connected to the upper electrode 164 via the auxiliary electrode 172.
The piezoelectric element and the actuator 106
Exchanges signals with external devices. Upper electrode terminal 1
The lower electrode terminal 68 and the lower electrode terminal 170 have a height equal to or higher than the height of the piezoelectric element including the electrode and the piezoelectric layer.

FIG. 27 shows a method of manufacturing the actuator 106 shown in FIG. First, Green Sheet 940
Through holes 940 using press or laser processing
Perforate a. The green sheet 940 is the substrate 1 after firing.
It will be 78. The green sheet 940 is formed of a material such as ceramic. Next, the green sheet 941 is laminated on the surface of the green sheet 940. Green sheet 94
1 becomes the diaphragm 176 after firing. Green sheet 9
41 is formed of a material such as zirconia oxide. next,
The conductive layer 942 and the piezoelectric layer 1 on the surface of the green sheet 941
60, and a conductive layer 944 are sequentially formed by a method such as pressure film printing. The conductive layer 942 will later become the lower electrode 166, and the conductive layer 944 will later become the upper electrode 164. Next, the formed green sheet 940, green sheet 941, conductive layer 942, piezoelectric layer 160, and conductive layer 944 are dried and fired. The spacer members 947 and 948 raise the heights of the upper electrode terminal 168 and the lower electrode terminal 170 to be higher than the piezoelectric element. The spacer members 947 and 948 are
The same material as the green sheets 940 and 941 is printed or the green sheets are laminated. The upper electrode terminal 16 made of a noble metal is formed by the spacer members 947 and 948.
8 and the lower electrode terminal 170 require less material,
Since the thickness of the upper electrode terminal 168 and the lower electrode terminal 170 can be reduced, the upper electrode terminal 168 and the lower electrode terminal 1
70 can be printed with high accuracy, and the height can be further stabilized.

When the connection portion 944 'to the conductive layer 944 and the spacer members 947 and 948 are formed at the same time when the conductive layer 942 is formed, the upper electrode terminal 168 and the lower electrode terminal 170 can be easily formed or firmly fixed. Can be. Finally, upper electrode terminals 168 and lower electrode terminals 170 are formed in end regions of the conductive layers 942 and 944. When forming the upper electrode terminal 168 and the lower electrode terminal 170, the upper electrode terminal 168 and the lower electrode terminal 170 are formed.
Is formed so as to be electrically connected to the piezoelectric layer 160.

FIG. 28 shows still another embodiment of the ink cartridge to which the present invention is applied. FIG. 28 (A)
FIG. 3 is a sectional view of the bottom of the ink cartridge according to the present embodiment. The ink cartridge of the present embodiment has a through hole 1c in the bottom surface 1a of the container 1 that stores ink. The bottom of the through hole 1c is closed by the actuator 650 to form an ink reservoir.

FIG. 28B shows a detailed cross section of the actuator 650 and the through hole 1c shown in FIG. FIG. 28C illustrates a plane of the actuator 650 and the through hole 1c illustrated in FIG. The actuator 650 has the diaphragm 72 and the piezoelectric element 73 fixed to the diaphragm 72. The actuator 650 is fixed to the bottom surface of the container 1 such that the piezoelectric element 73 faces the through hole 1c via the vibration plate 72 and the substrate 71. The diaphragm 72 is elastically deformable and has ink resistance.

Depending on the amount of ink in the container 1, the piezoelectric element 7
3 and the amplitude and frequency of the back electromotive force generated by the residual vibration of the diaphragm 72 change. The through hole 1c is formed at a position facing the actuator 650, and a minimum amount of ink is secured in the through hole 1c. Therefore, by measuring in advance the characteristics of the vibration of the actuator 650 determined by the amount of ink secured in the through hole 1c, the ink end of the container 1 can be reliably detected.

FIG. 29 shows another embodiment of the through hole 1c. In each of FIGS. 29A, 29B, and 29C, the left-side diagram shows a state where there is no ink K in the through-hole 1c, and the right-side diagram shows a state where the ink K remains in the through-hole 1c. Is shown. In the embodiment of FIG. 28, the side surface of the through hole 1c is formed as a vertical wall. In FIG. 29 (A), the side surface 1d of the through-hole 1c is oblique in the up-down direction and expands outward. In FIG. 29B, step portions 1e and 1f are formed on the side surface of the through hole 1c. The upper step 1f is wider than the lower step 1e. In FIG. 29 (C), the through-hole 1c has a groove 1g extending in the direction in which the ink K is easily discharged, that is, in the direction of the ink supply port 2.

According to the shapes of the through holes 1c shown in FIGS. 29A to 29C, the amount of the ink K in the ink reservoir can be reduced. Therefore, M'cav described with reference to FIGS.
Can be reduced compared to M'max,
Since the vibration characteristic of the actuator 650 at the time of ink end can be made significantly different from the case where a printable amount of the ink K remains in the container 1, the ink end can be detected more reliably.

FIG. 30 is a perspective view showing another embodiment of the actuator. The actuator 660 has a packing 76 outside the through hole 1c of the substrate or the mounting plate 78 that constitutes the actuator 660. A caulking hole 77 is formed on the outer periphery of the actuator 660. The actuator 660 is fixed to the container 1 by swaging through the swaging hole 77.

FIGS. 31A and 31B are perspective views showing still another embodiment of the actuator. In the present embodiment, the actuator 670 is connected to the recess forming substrate 80.
And a piezoelectric element 82. A concave portion 81 is formed on one surface of the concave portion forming substrate 80 by a method such as etching, and a piezoelectric element 82 is mounted on the other surface. The bottom of the recess 81 in the recess forming substrate 80 functions as a vibration region. Therefore, the vibration region of the actuator 670 is defined by the periphery of the concave portion 81. The actuator 670 is the same as the actuator 1 according to the embodiment of FIG.
06, it is similar to the structure in which the substrate 178 and the diaphragm 176 are integrally formed. Therefore, the manufacturing process when manufacturing the ink cartridge can be shortened, and the cost is reduced. The actuator 670 has a size that can be embedded in the through hole 1c provided in the container 1.
Thereby, the concave portion 81 can also function as a cavity. The actuator 106 according to the embodiment of FIG. 20 is replaced with the actuator 67 according to the embodiment of FIG.
Similarly to the case of 0, it may be formed so that it can be embedded in the through hole 1c.

FIG. 32 is a perspective view showing a structure in which the actuator 106 is integrally formed as the mounting module body 100. FIG. The module body 100 is mounted at a predetermined position of the container 1 of the ink cartridge. Module body 100
Is configured to detect a consumption state of the liquid in the container 1 by detecting at least a change in acoustic impedance in the ink liquid. The module 100 of the present embodiment has a liquid container mounting portion 101 for mounting the actuator 106 to the container 1. The liquid container mounting portion 101 has a structure in which a cylindrical portion 116 containing an actuator 106 oscillated by a drive signal is mounted on a base 102 having a substantially rectangular plane. Module body 100
Is configured such that the actuator 106 of the module 100 cannot be contacted from the outside when the cartridge is mounted on the ink cartridge.
Can be protected from external contact. In addition, the tip side edge of the cylindrical portion 116 is rounded, so that it can be easily fitted when the cylindrical portion 116 is mounted in a hole formed in the ink cartridge.

FIG. 33 shows the module 1 shown in FIG.
FIG. 2 is an exploded view showing the configuration of the 00. Module body 100
The liquid container mounting portion 101 made of resin and the plate 1
10 and a piezoelectric device mounting portion 105 having a concave portion 113. Further, the module body 100 includes lead wires 104a and 104b, an actuator 106, and a film 108. Preferably, plate 110
Is formed from a material that is not easily rusted, such as stainless steel or a stainless alloy. The cylindrical portion 116 and the base 102 included in the liquid container mounting portion 101 are formed with an opening 114 at the center so as to accommodate the lead wires 104a and 104b, so that the actuator 106, the film 108, and the plate 110 can be accommodated. A recess 113 is formed. The actuator 106 is joined to the plate 110 via the film 108, and the plate 110 and the actuator 106 are fixed to the liquid container mounting portion 101. Therefore, the lead wires 104a and 104b, the actuator 106, the film 108 and the plate 11
0 is integrally attached to the liquid container attaching portion 101. Lead wires 104a and 104b couple to the upper and lower electrodes of actuator 106, respectively, to transmit drive signals to the piezoelectric layer while the actuator 10
The signal of the resonance frequency detected by 6 is transmitted to a recording device or the like. The actuator 106 oscillates temporarily based on the drive signal transmitted from the lead wires 104a and 104b. The actuator 106 undergoes residual vibration after oscillation, and generates a back electromotive force by the vibration. At this time, by detecting the oscillation period of the back electromotive force waveform,
The resonance frequency corresponding to the consumption state of the liquid in the liquid container can be detected. The film 108 bonds the actuator 106 and the plate 110 to make the actuator liquid-tight. The film 108 is preferably formed of a polyolefin or the like, and is preferably bonded by heat fusion.

The plate 110 has a circular shape.
The second opening 114 is formed in a cylindrical shape. The actuator 106 and the film 108 are formed in a rectangular shape. The lead wire 104, the actuator 106, the film 108, and the plate 110 may be detachable from the base 102. The base 102, the lead wires 104, the actuator 106, the film 108, and the plate 110 are symmetrically arranged with respect to the central axis of the module 100. Further, the centers of the base 102, the actuator 106, the film 108, and the plate 110 are disposed substantially on the central axis of the module 100.

The area of the opening 114 of the base 102 is formed larger than the area of the vibration region of the actuator 106. Actuator 10 at the center of plate 110
A through hole 112 is formed at a position facing the vibrating portion of No. 6. As shown in FIGS. 20 and 21, a cavity 162 is formed in the actuator 106, and the through hole 112 and the cavity 162 together form an ink reservoir. The thickness of the plate 110 is preferably smaller than the diameter of the through hole 112 in order to reduce the influence of the residual ink. For example, the depth of the through hole 112 is one third of its diameter.
The size is preferably as follows. The through hole 112 is
It has a substantially perfect circular shape symmetric with respect to the central axis of the module body 100. The area of the through hole 112 is larger than the opening area of the cavity 162 of the actuator 106.
The periphery of the cross section of the through hole 112 may be tapered or stepped. The module 100 is mounted on the side, top, or bottom of the container 1 so that the through holes 112 face the inside of the container 1. When the ink is consumed and the ink around the actuator 106 runs out, the resonance frequency of the actuator 106 greatly changes, so that a change in the ink level can be detected.

FIG. 34 is a perspective view showing another embodiment of the module body. Module body 400 of the present embodiment
In the figure, a piezoelectric device mounting portion 405 is formed on a liquid container mounting portion 401. In the liquid container mounting portion 401, a columnar column portion 403 is formed on a base 402 on a square whose plane is almost rounded. Further, the piezoelectric device mounting portion 405 includes a plate-shaped element 406 standing on the cylindrical portion 403 and a concave portion 41.
3 inclusive. The recess 41 provided on the side surface of the plate element 406
An actuator 106 is disposed at 3. Note that the tip of the plate-shaped element 406 is chamfered at a predetermined angle so that it can be easily fitted into a hole formed in the ink cartridge.

FIG. 35 shows the module 4 shown in FIG.
FIG. 2 is an exploded perspective view showing the configuration of the 00. Similarly to the module 100 shown in FIG. 32, the module 400 includes a liquid container mounting portion 401 and a piezoelectric device mounting portion 405. The liquid container mounting portion 401 includes a base 402 and a cylindrical portion 4.
03, and the piezoelectric device mounting portion 405 has a plate-shaped element 406 and a concave portion 413. The actuator 106 is fixed to the concave portion 413 by being joined to the plate 410. The module 400 includes lead wires 404a and 404
b, the actuator 106, and the film 408.

According to the present embodiment, the plate 410 has a rectangular shape, and the opening 414 provided in the plate-like element 406 is provided.
Is formed in a rectangular shape. The lead wires 404a and 404b, the actuator 106, the film 408, and the plate 410 may be configured to be detachable from the base 402. Actuator 106, film 40
8 and the plate 410 are symmetrically arranged with respect to a central axis extending through the center of the opening 414 and extending in a direction perpendicular to the plane of the opening 414. Further, the centers of the actuator 406, the film 408, and the plate 410 are disposed substantially on the central axis of the opening 414.

The area of the through hole 412 provided at the center of the plate 410 is
62 are formed larger than the area of the opening. The cavity 162 and the through hole 412 of the actuator 106 together form an ink reservoir. The thickness of the plate 410 is smaller than the diameter of the through hole 412, for example, the thickness of the through hole 41.
It is preferable to set the size to one third or less of the diameter of 2. The through hole 412 has a substantially perfect circular shape symmetric with respect to the central axis of the module 400. The periphery of the cross section of the through hole 412 may be tapered or stepped. The module 400 can be mounted on the bottom of the container 1 so that the through hole 412 is arranged inside the container 1. Since the actuator 106 is disposed in the container 1 so as to extend in the vertical direction, the height of the base 402 is changed to change the height at which the actuator 106 is disposed in the container 1 so that the setting of the ink end point can be performed. Can be changed easily.

FIG. 36 shows still another embodiment of the module. Similarly to the module 100 shown in FIG. 32, the module 500 shown in FIG. 36 includes a liquid container mounting portion 501 having a base 502 and a column 503. The module 500 further includes lead wires 504a and 504b, an actuator 106, a film 508, and a plate 510. Liquid container mounting part 50
An opening 514 is formed in the center of the base 502 included in 1 to accommodate the lead wires 504a and 504b, and a recess 513 is formed to accommodate the actuator 106, the film 508, and the plate 510. The actuator 106 is fixed to the piezoelectric device mounting portion 505 via the plate 510. Therefore, the lead wires 504a and 504b, the actuator 106, the film 508, and the plate 510 are connected to the liquid container mounting portion 5
01 is integrally attached. In the module body 500 of the present embodiment, a cylindrical portion 503 whose upper surface is oblique in the vertical direction is formed on a base having a square shape with a substantially round corner. The actuator 106 is disposed on a concave portion 513 provided obliquely in the vertical direction on the upper surface of the columnar portion 503.

The tip of the module 500 is inclined, and the actuator 106 is mounted on the inclined surface. Therefore, when the module 500 is mounted on the bottom or the side of the container 1, the actuator 106 is inclined with respect to the vertical direction of the container 1. The inclination angle of the tip of the module 500 is approximately 30 ° to 60 ° in view of the detection performance.
It is desirable to be between.

The module 500 includes the actuator 1
06 is mounted on the bottom or side of the container 1 so as to be placed in the container 1. When the module 500 is mounted on the side of the container 1, the actuator 106 is attached to the container 1 so as to face the upper side, the lower side, or the side of the container 1 while being inclined. On the other hand, when the module 500 is mounted on the bottom of the container 1, the actuator 10
6 is preferably attached to the container 1 so as to face the ink supply port side of the container 1 while being inclined.

FIG. 37 shows the module 1 shown in FIG.
FIG. 4 is a cross-sectional view near the bottom of the ink container when 00 is mounted on the container 1. The module 100 is mounted so as to penetrate the side wall of the container 1. An O-ring 365 is provided on the joint surface between the side wall of the container 1 and the module 100 to keep the module 100 and the container 1 liquid-tight. Module body 10 so that it can be sealed with an O-ring
0 preferably has a columnar portion as described in FIG. When the tip of the module 100 is inserted into the container 1, the ink in the container 1 comes into contact with the actuator 106 through the through hole 112 of the plate 110.
Since the resonance frequency of the residual vibration of the actuator 106 differs depending on whether the surroundings of the vibrating portion of the actuator 106 are liquid or gas, the ink consumption state can be detected using the module 100. Also, the module body 10
0, the module 400 shown in FIG.
The module 500 shown in FIG. 6 or the modules 700A and 700B and the mold structure 600 shown in FIG.

FIG. 38A is a sectional view of the ink container when the module 700B is mounted on the container 1. FIG. In this embodiment, the module 700B is used as one of the mounting structures.
Use The module 700B is mounted on the container 1 such that the liquid container mounting portion 360 projects into the container 1. A through hole 370 is formed in the mounting plate 350, and the through hole 370 and the vibrating portion of the actuator 106 face. Further, a hole 382 is formed in the bottom wall of the module 700B, and a piezoelectric device mounting portion 363 is formed. The actuator 106 is disposed so as to close one of the holes 382. Therefore, the ink comes into contact with the vibration plate 176 via the hole 382 of the piezoelectric device mounting portion 363 and the through hole 370 of the mounting plate 350. The hole 382 of the piezoelectric device mounting portion 363 and the through hole 370 of the mounting plate 350 together form an ink reservoir. The piezoelectric device mounting portion 363 and the actuator 106 are attached to the mounting plate 35.
0 and fixed by a film member. The connecting portion between the liquid container mounting portion 360 and the container 1 has a sealing structure 3
72 are provided. The sealing structure 372 may be formed of a plastic material such as a synthetic resin, or may be formed of an O-ring. Although the module 700B of FIG. 38A and the container 1 are separate bodies, the piezoelectric device mounting portion of the module 700B may be configured as a part of the container 1 as shown in FIG.

The module 700B shown in FIG.
The lead wires shown in FIGS. 32 to 36 do not need to be embedded in the module. Therefore, the molding process is simplified. Further, the module 700B can be replaced, and the module 700B can be recycled.

When the ink cartridge is shaken, the ink adheres to the upper surface or the side surface of the container 1 and the ink dripping from the upper surface or the side surface of the container 1
, The actuator 106 may malfunction. However, since the liquid container mounting portion 360 of the module 700B protrudes into the container 1, the actuator 106 does not malfunction due to ink dripping from the upper surface or the side surface of the container 1.

In the embodiment shown in FIG. 38A, only the vibration plate 176 and a part of the mounting plate 350 are mounted on the container 1 so as to come into contact with the ink in the container 1. FIG.
In the embodiment of (A), the lead wires 104a, 104b, 404a, 404b, and 50 shown in FIGS.
The embedding of the electrodes 4a and 504b in the module body becomes unnecessary. Therefore, the molding process is simplified. Further, the actuator 106 can be replaced, and recycling can be performed.

FIG. 38B is a sectional view of an ink container as an embodiment when the actuator 106 is mounted on the container 1. In the ink cartridge according to the embodiment shown in FIG. 38B, the protection member 361 is attached to the container 1 separately from the actuator 106. Therefore, although the protection member 361 and the actuator 106 are not integrated as a module, the protection member 361 can protect the actuator 106 from being touched by a user's hand. A hole 380 provided on the front surface of the actuator 106 is provided on a side wall of the container 1.
The actuator 106 includes a piezoelectric layer 160, an upper electrode 16
4. Lower electrode 166, diaphragm 176 and mounting plate 3
50. A diaphragm 176 is provided on the upper surface of the mounting plate 350.
Are formed, and a lower electrode 166 is formed on the upper surface of the diaphragm 176. The piezoelectric layer 160 is formed on the upper surface of the lower electrode 166.
Is formed, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Therefore, the main part of the piezoelectric layer 160 is:
The main portion of the upper electrode 164 and the main portion of the lower electrode 166 are formed so as to be sandwiched from above and below. The circular portions that are the main portions of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element. The piezoelectric element is formed on the vibration plate 176. The vibration area of the piezoelectric element and the vibration plate 176 is a vibration part where the actuator actually vibrates. The mounting plate 350 has a through hole 370
Is provided. Further, a hole 380 is formed in the side wall of the container 1. Therefore, the ink is supplied to the holes 3 of the container 1.
The diaphragm 176 is brought into contact with the diaphragm 176 through the through hole 370 of the mounting plate 350. The hole 380 of the container 1 and the through hole 370 of the mounting plate 350 together form an ink reservoir. In the embodiment of FIG. 38B, since the actuator 106 is protected by the protection member 361, the actuator 106 can be protected from contact with the outside.

Note that, instead of the mounting plate 350 in the embodiment of FIGS. 38A and 38B, the substrate 17 of FIG.
8 may be used.

FIG. 38C shows an embodiment having a mold structure 600 including the actuator 106. In this embodiment, the mold structure 60 is used as one of the mounting structures.
Use 0. The mold structure 600 has the actuator 106 and the mold section 364. The actuator 106 and the mold part 364 are integrally formed.
The mold section 364 is formed of a plastic material such as a silicone resin. The mold part 364 has a lead wire 362 inside. Mold part 364 is formed to have two legs extending from actuator 106. The ends of the two legs of the mold portion 364 are formed in a hemispherical shape in order to fix the mold portion 364 and the container 1 in a liquid-tight manner. The mold part 364 is mounted on the container 1 so that the actuator 106 projects into the container 1, and the vibrating part of the actuator 106 contacts the ink in the container 1. The upper electrode 164, the piezoelectric layer 160, and the lower electrode 166 of the actuator 106 are protected from the ink by the mold portion 364.

The mold structure 600 shown in FIG.
Sealing structure 37 between mold part 364 and container 1
Since the ink 2 is not necessary, the ink hardly leaks from the container 1. Since the mold structure 600 does not protrude from the outside of the container 1, the actuator 106 can be protected from contact with the outside. When the ink cartridge shakes, the ink adheres to the upper surface or the side surface of the container 1,
When the ink dripping from the upper surface or the side surface of the container 1 comes into contact with the actuator 106, the actuator 106 may malfunction. Mold structure 6
In the case of 00, the actuator 106 does not malfunction due to ink dripping from the upper surface or the side surface of the container 1 because the mold portion 364 protrudes into the container 1.

FIG. 39 shows an embodiment of an ink cartridge and an ink jet recording apparatus using the actuator 106 shown in FIG. The plurality of ink cartridges 180 are mounted on an inkjet recording apparatus having a plurality of ink introduction portions 182 and holders 184 corresponding to the respective ink cartridges 180. The plurality of ink cartridges 180 store inks of different types, for example, colors. Multiple ink cartridges 1
An actuator 106 as a means for detecting at least acoustic impedance is mounted on the bottom surface of each of the actuators 80. By mounting the actuator 106 on the ink cartridge 180, the remaining amount of ink in the ink cartridge 180 can be detected.

FIG. 40 shows details around the head of the ink jet recording apparatus. The ink jet recording apparatus includes an ink introduction unit 182, a holder 184, a head plate 1
86, and a nozzle plate 188. A plurality of nozzles 190 for ejecting ink are formed on the nozzle plate 188. The ink introduction section 182 has an air supply port 181 and an ink introduction port 183. The air supply port 181 supplies air to the ink cartridge 180. The ink inlet 183 introduces ink from the ink cartridge 180. The ink cartridge 180 has an air inlet 185 and an ink supply port 187. The air inlet 185 introduces air from the air supply port 181 of the ink inlet 182. The ink supply port 187 supplies ink to the ink introduction port 183 of the ink introduction unit 182. When the ink cartridge 180 introduces air from the ink introduction unit 182, the ink cartridge 180
The supply of ink to 82 is prompted. The holder 184 communicates the ink supplied from the ink cartridge 180 via the ink introduction unit 182 to the head plate 186.

FIG. 41 shows another embodiment of the ink cartridge 180 shown in FIG. In the ink cartridge 180A shown in FIG. 41A, the actuator 106 is mounted on a bottom surface 194a formed obliquely in the vertical direction. Inside the ink container 194 of the ink cartridge 180, the wave barrier 19 is located at a predetermined height from the inner bottom surface of the ink container 194 and faces the actuator 106.
2 are provided. Since the actuator 106 is mounted obliquely with respect to the vertical direction of the ink container 194, the ink can be swept well.

A gap filled with ink is formed between the actuator 106 and the break wall 192. Also,
The space between the wave preventing wall 192 and the actuator 106 is so large that the ink is not held by the capillary force. When the ink container 194 rolls, a wave of ink is generated inside the ink container 194 due to the roll, and due to the impact, a gas or a bubble is detected by the actuator 106, and the actuator 106 may malfunction. By providing the wave preventing wall 192, a wave of ink near the actuator 106 can be prevented, and malfunction of the actuator 106 can be prevented.

The ink cartridge 180 shown in FIG.
The B actuator 106 is mounted on the side wall of the supply port of the ink container 194. In the vicinity of the ink supply port 187, the actuator 106
4 may be mounted on the side wall or bottom surface. Further, it is preferable that the actuator 106 is mounted at the center of the ink container 194 in the width direction. The ink is supplied to the ink supply port 187.
Is supplied to the outside through the
6 is provided near the ink supply port 187 so that the ink and the actuator
And make sure contact. Therefore, the actuator 10
No. 6 can reliably detect the time of the ink near end.

Further, by providing the actuator 106 near the ink supply port 187, when the ink container is mounted on the cartridge holder on the carriage, the positioning between the actuator 106 on the ink container and the contact on the carriage can be ensured. Become. The most important reason for the connection between the ink container and the carriage is a reliable connection between the ink supply port and the supply needle. This is because if there is any deviation, the tip of the supply needle is damaged, or a sealing structure such as an O-ring is damaged, and the ink leaks out. In order to prevent such a problem, an ink jet printer usually has a special structure that allows accurate alignment when mounting an ink container on a carriage. Therefore, by arranging the actuator near the supply port, the positioning of the actuator can be simultaneously ensured. further,
By mounting the actuator 106 at the center in the width direction of the ink container 194, the alignment can be performed more reliably. This is because when the ink container swings around the center line in the width direction when the ink container is mounted on the holder, the swing is the least.

FIG. 42 shows still another embodiment of the ink cartridge 180. 42A is a sectional view of the ink cartridge 180C, FIG. 42B is an enlarged sectional view of the side wall 194b of the ink cartridge 180C shown in FIG. 42A, and FIG. It is a perspective view. The ink cartridge 180C has a circuit board 610 on which the semiconductor storage means 7 and the actuator 106 are the same.
Is formed on. As shown in FIGS. 42B and 42C, the semiconductor storage means 7 is formed above the circuit board 610, and the actuator 106 is formed below the semiconductor storage means 7 on the same circuit board 610. O-ring 614 is shaped to surround the periphery of actuator 106.
Is mounted on the side wall 194b. A plurality of caulking portions 616 for joining the circuit board 610 to the ink container 194 are formed on the side wall 194b. By bonding the circuit board 610 to the ink container 194 by the caulking portion 616 and pressing the odd-shaped O-ring 614 against the circuit board 610,
The outside and inside of the ink cartridge are kept liquid-tight, while allowing the vibration area of the actuator 106 to come into contact with the ink.

The terminal 612 is formed in the semiconductor storage means 7 and in the vicinity of the semiconductor storage means 7. The terminal 612 exchanges signals between the semiconductor storage means 7 and the outside such as an ink jet storage device. The semiconductor storage means 7 may be constituted by a rewritable semiconductor memory such as an EEPROM. Since the semiconductor storage means 7 and the actuator 106 are formed on the same circuit board 610, only one mounting step is required when mounting the actuator 106 and the semiconductor storage means 7 on the ink cartridge 180C. Further, the working process at the time of manufacturing and recycling the ink cartridge 180C is simplified. Further, since the number of parts is reduced, the ink cartridge 180
The manufacturing cost of C can be reduced.

The actuator 106 is connected to the ink container 19.
4 is detected. Semiconductor storage means 7
Stores ink information such as the remaining amount of ink detected by the actuator 106. That is, the semiconductor storage means 7 stores information on characteristic parameters such as characteristics of the ink and the ink cartridge used for detection. The semiconductor storage means 7 stores the ink in the ink container 194 in advance when the ink is full, that is, when the ink is filled in the ink container 194, or when the ink is in the end, that is, when the ink
The resonance frequency when the ink in 94 is consumed is stored as one of the characteristic parameters. The resonance frequency of the full or end state of the ink in the ink container 194 may be stored when the ink container is first attached to the ink jet recording apparatus. In addition, the resonance frequency of the ink container 194 in the full or end state of the ink container
4 may be stored during manufacture. The resonance frequency when the ink in the ink container 194 is full or end is stored in advance in the semiconductor storage means 7, and the data of the resonance frequency is read out on the ink jet recording apparatus side to correct the variation in detecting the remaining ink amount. Therefore, it is possible to accurately detect that the remaining amount of ink has decreased to the reference value.

FIG. 43 shows still another embodiment of the ink cartridge 180. The ink cartridge 180D shown in FIG.
Are mounted with a plurality of actuators 106. A plurality of integrally formed actuators 106 shown in FIG.
It is preferable to use the plurality of actuators 106. The plurality of actuators 106 are arranged on the side wall 194b at intervals in the vertical direction. The plurality of actuators 106 are vertically spaced from each other on the side wall 19.
By arranging it at 4b, the remaining amount of ink can be detected in a stepwise manner.

The ink cartridge 1 shown in FIG.
At 80E, an actuator 606 that is long in the vertical direction is mounted on the side wall 194b of the ink container 194. The change in the remaining amount of ink in the ink container 194 can be continuously detected by the vertically long actuator 606.
It is preferable that the length of the actuator 606 be at least half the height of the side wall 194b.
In, the actuator 606 has a length from substantially the upper end to the substantially lower end of the side wall 194b.

The ink cartridge 1 shown in FIG.
80F is the ink cartridge 1 shown in FIG.
As in the case of 80D, a plurality of actuators 106 are mounted on the side wall 194b of the ink container 194, and a wave preventing wall 192 that is long in the vertical direction is provided at a predetermined interval in the face of the plurality of actuators 106. It is preferable to use a plurality of actuators 106 integrally formed as shown in FIG. A gap filled with ink is formed between the actuator 106 and the break wall 192. Further, the gap between the wave preventing wall 192 and the actuator 106 is so large that the ink is not held by the capillary force. When the ink container 194 rolls, a wave of ink is generated inside the ink container 194 due to the roll, and a gas or a bubble is detected by the actuator 106 due to the impact, and the actuator 106 may malfunction. By providing the wave preventing wall 192 as in the present invention, it is possible to prevent ripples of ink near the actuator 106 and prevent the actuator 106 from malfunctioning. In addition, breakwater 1
Numeral 92 prevents bubbles generated by the ink swinging from entering the actuator 106.

FIG. 44 shows still another embodiment of the ink cartridge 180. The ink cartridge 180G of FIG. 44A has a plurality of partitions 212 extending downward from the upper surface 194c of the ink container 194. Since the lower end of each partition 212 and the bottom surface of the ink container 194 are spaced apart by a predetermined distance, the bottom of the ink container 194 is in communication. The ink cartridge 180G includes a plurality of storage chambers 21 partitioned by a plurality of partition walls 212, respectively.
3 The bottoms of the plurality of storage chambers 213 communicate with each other. In each of the plurality of storage chambers 213, the actuator 106 is mounted on the upper surface 194c of the ink container 194. The integrally formed actuator 106 shown in FIG.
It is preferable to use as. Actuator 106
Is disposed substantially at the center of the upper surface 194c of the storage chamber 213 of the ink container 194. The capacity of the storage chamber 213 is largest on the side of the ink supply port 187, and as the distance from the ink supply port 187 to the depth of the ink container 194 increases, the capacity of the storage chamber 213 increases.
Is gradually becoming smaller. Therefore, the interval at which the actuators 106 are arranged is determined by the ink supply port 187.
The side is wide, and becomes narrower as the distance from the ink supply port 187 to the depth of the ink container 194 increases.

The ink is discharged from the ink supply port 187 and the air enters through the air introduction port 185.
The ink is consumed into the accommodation room 213 at the back of 0G.
For example, while the ink in the storage chamber 213 closest to the ink supply port 187 is consumed and the water level of the ink in the storage chamber 213 closest to the ink supply port 187 is lowered, the other storage chambers 213 are filled with ink. ing. Ink supply port 1
When the ink in the storage chamber 213 closest to 87 is exhausted, air enters the second storage chamber 213 counted from the ink supply port 187, and the ink in the second storage chamber 213 starts to be consumed. The water level of the ink in the second storage chamber 213 starts to drop. At this point, the third and subsequent storage chambers 213 counted from the ink supply chamber 187 are filled with ink. In this manner, ink is consumed in order from the storage chamber 213 near the ink supply port 187 to the storage chamber 213 far from the ink supply port 187.

As described above, the actuator 106 is mounted on the upper surface 19 of the ink container 194 for each of the storage chambers 213.
4C, the actuator 106 can detect a decrease in the amount of ink in a stepwise manner. Furthermore, the capacity of the storage chamber 213 is
7, the time interval at which the actuator 106 detects a decrease in the amount of ink gradually decreases, and the frequency can be increased as the actuator 106 approaches the ink end.

The ink cartridge 180 shown in FIG.
H has one partition 212 extending downward from the upper surface 194c of the ink container 194. Since the lower end of the partition wall 212 and the bottom surface of the ink container 194 are spaced apart from each other by a predetermined distance, the bottom of the ink container 194 is in communication. The ink cartridge 180 </ b> H is divided into two by a partition 212.
It has chamber accommodation rooms 213a and 213b. Accommodation room 21
The bottoms of 3a and 213b communicate with each other. The capacity of the storage chamber 213a on the ink supply port 187 side is
7 is larger than the capacity of the accommodation room 213b at the back.
The capacity of the accommodation room 213b is preferably smaller than half the capacity of the accommodation room 213a.

The actuator 106 is mounted on the upper surface 194c of the accommodation room 213b. Further, a buffer 214 is formed in the storage chamber 213b, which is a groove for catching bubbles that enter during the manufacture of the ink cartridge 180H. FIG.
In (B), the buffer 214 includes an ink container 194.
Is formed as a groove extending upward from the side wall 194b of the upper surface.
The buffer 214 captures air bubbles that have entered the ink storage chamber 213b.
Can be prevented from being erroneously detected as being out of ink. Further, by providing the actuator 106 on the upper surface 194c of the storage chamber 213b, the amount of ink in the storage chamber 213a grasped by the dot counter can be compared with the amount of ink from the detection of the ink near end to the complete ink end state. By performing the correction corresponding to the consumption state, the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length and interval of the partition 212, the amount of ink that can be consumed after the detection of the ink near end can be changed.

FIG. 44C shows a state in which the porous member 21 is stored in the storage chamber 213b of the ink cartridge 180I shown in FIG.
6 are filled. The porous member 216 is provided in the accommodation room 21.
3b is installed so as to fill the entire space from the upper surface to the lower surface. The porous member 216 contacts the actuator 106. When the ink container falls down, or during reciprocation on the carriage, air enters the ink storage chamber 213b, which may cause the actuator 106 to malfunction. However, if the porous member 216 is provided, it is possible to catch air and prevent air from entering the actuator 106. In addition, the porous member 2
Since the ink container 16 holds the ink, the ink container shakes, so that it is possible to prevent the ink from being applied to the actuator 106 and the actuator 106 from erroneously detecting the absence of the ink as the presence of the ink. It is preferable that the porous member 216 be installed in the storage chamber 213 having the smallest capacity. Also,
The actuator 106 is mounted on the upper surface 194c of the housing material 213b.
, The amount of ink from the detection of the ink near end to the complete ink end state can be corrected, and the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length and interval of the partition 212, the amount of ink that can be consumed after the detection of the ink near end can be changed.

FIG. 44D shows an ink cartridge 180J in which the porous member 216 of the ink cartridge 180I of FIG. 44C is constituted by two types of porous members 216A and 216B having different hole diameters. The porous member 216A is arranged above the porous member 216B. The pore size of the upper porous member 216A is larger than the pore size of the lower porous member 216B. Alternatively, the porous member 216A is formed of a member having a lower liquid affinity than the porous member 216B. Porous member 21 with small pore diameter
Since 6B has a larger capillary force than the porous member 216A having a larger pore diameter, the ink in the storage chamber 213b is collected and held in the lower porous chamber member 216B. Therefore,
Once the air reaches the actuator 106 and detects the absence of ink, the ink does not reach the actuator again to detect the presence of ink. Further, the ink is absorbed by the porous member 216B farther from the actuator 106, so that the ink in the vicinity of the actuator 106 is more easily separated, and the amount of change in the acoustic impedance change when detecting the presence or absence of the ink is increased. Further, by providing the actuator 106 on the upper surface 194c of the storage material 213b, the amount of ink from the detection of the ink near end to the complete ink end state can be corrected, and the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length and interval of the partition 212, the amount of ink that can be consumed after the detection of the ink near end can be changed.

FIG. 45 is a sectional view showing an ink cartridge 180K which is another embodiment of the ink cartridge 180I shown in FIG. 44 (C). The porous member 216 of the ink cartridge 180 shown in FIG. 45 has a horizontal cross-sectional area below the porous member 216 in the ink container 19.
4 is designed so that it is compressed so as to gradually decrease toward the bottom surface, and the hole diameter is reduced. FIG.
The ink cartridge 180K shown in FIG.
Ribs are provided on the side wall to compress the lower hole diameter of the lower part 16. Since the pore diameter at the bottom of the porous member 216 is reduced by being compressed,
The ink is collected and held at the lower part of the porous member 216. Porous member 21 farther from actuator 106
The ink is absorbed in the lower part of the actuator 6 so that the actuator 1
Ink around 06 becomes better and the amount of change in acoustic impedance when detecting the presence or absence of ink becomes larger. Therefore, the actuator 1 mounted on the upper surface of the ink cartridge 180K due to the ink swaying.
06 is covered with ink and the actuator 10
6 can be prevented from erroneously detecting the absence of ink as the presence of ink.

On the other hand, in the ink cartridge 180L shown in FIGS. 45B and 45C, the horizontal cross-sectional area of the lower portion of the porous member 216 is smaller than the bottom surface of the ink container 194 in the width direction of the ink container 194. The horizontal cross-sectional area of the storage chamber is gradually reduced toward the bottom surface of the ink container 194 in order to compress the storage container so as to be gradually reduced. Since the pore diameter at the lower portion of the porous member 216 is reduced by being compressed, the ink is
16 are collected and held at the bottom. Since the ink is absorbed in the lower portion of the porous member 216B farther from the actuator 106, the ink in the vicinity of the actuator 106 is more easily separated, and the amount of change in the acoustic impedance change when detecting the presence or absence of the ink is increased. Therefore, it is possible to prevent the actuator 106 mounted on the upper surface of the ink cartridge 180L from being spilled with ink due to the shaking of the ink, and the actuator 106 from erroneously detecting absence of ink as presence of ink.

FIG. 46 shows still another embodiment of the ink cartridge using the actuator 106. FIG.
The ink cartridge 220A of (A) has a first partition 222 provided so as to extend downward from the upper surface of the ink cartridge 220A. Since a predetermined space is provided between the lower end of the first partition wall 222 and the bottom surface of the ink cartridge 220A, ink can flow into the ink supply port 230 through the bottom surface of the ink cartridge 220A. On the ink supply port 230 side from the first partition 222, a second partition 224 is formed so as to extend above the bottom surface of the ink cartridge 220A. Second
A predetermined distance is provided between the upper end of the partition 224 and the upper surface of the ink cartridge 220A, so that the ink can flow into the ink supply port 230 through the upper surface of the ink cartridge 220A.

The first partition 222 forms a first storage chamber 225 a at the back of the first partition 222 when viewed from the ink supply port 230. On the other hand, the second partition 224 is viewed from the ink supply port 230 by the second partition 224.
A second storage chamber 225b is formed in front of the second storage chamber 225b. The capacity of the first storage chamber 225a is larger than the capacity of the second storage chamber 225b. Capillary paths 227 are formed between the first partition wall 222 and the second partition wall 224 by providing an interval sufficient to cause capillary action. Therefore, the first
Is collected in the capillary channel 227 by the capillary force of the capillary channel 227. Therefore, it is possible to prevent gas and bubbles from entering the second storage chamber 225b. Further, the water level of the ink in the second storage chamber 225b can be stably gradually lowered. Ink supply port 23
0, the first accommodation room 225a is the second accommodation room 2
25b, the first storage chamber 22
After the ink in 5a is consumed, the ink in the second storage chamber 225b is consumed.

The actuator 106 is provided on the side wall of the ink cartridge 220A on the ink supply port 230 side, that is, on the side wall of the second storage chamber 225b on the ink supply port 230 side.
Is installed. The actuator 106 detects a state of ink consumption in the second storage chamber 225b. By mounting the actuator 106 on the side wall of the second storage chamber 225b, it is possible to stably detect the remaining amount of ink at a point closer to the ink end. Further, by changing the height at which the actuator 106 is mounted on the side wall of the second storage chamber 225b, it is possible to freely set the time when the remaining amount of the ink reaches the ink end. By supplying ink from the first storage chamber 225a to the second storage chamber 225b by the capillary channel 227,
The actuator 106 includes an ink cartridge 220A
Because the ink is not affected by the roll of the ink,
The actuator 106 can reliably measure the remaining amount of ink. Further, since the capillary channel 227 holds the ink, the ink flows from the second storage chamber 225b to the first storage chamber 225a.
Prevent backflow to

[0214] On the upper surface of the ink cartridge 220A,
A check valve 228 is provided. When the ink cartridge 220A rolls by the check valve 228,
Ink can be prevented from leaking out of the ink cartridge 220A. Further, by installing the check valve 228 on the upper surface of the ink cartridge 220A, evaporation of ink from the ink cartridge 220A can be prevented. The ink in the ink cartridge 220A is consumed, and the negative pressure in the ink cartridge 220A is reduced by the check valve 22.
When the pressure exceeds 8, the check valve 228 opens to draw air into the ink cartridge 220A, and then closes to keep the pressure inside the ink cartridge 220A constant.

FIGS. 46 (C) and (D) show the check valve 228.
3 shows a cross section of the detail. The check valve 228 in FIG.
It has a valve 232 having vanes 232a formed of rubber. Vent hole 2 with the outside of ink cartridge 220
The ink cartridge 2 faces the blade 232a.
20. The blades 232a allow the ventilation holes 23
3 are opened and closed. The check valve 228 serves to reduce the amount of ink in the ink cartridge 220 and
When the negative pressure within zero exceeds the pressure of the check valve 228, the blade 23
2a opens inside the ink cartridge 220 and takes in external air into the ink cartridge 220. The check valve 228 in FIG. 46D includes a valve 232 and a spring 235 formed of rubber. When the negative pressure in the ink cartridge 220 exceeds the pressure of the check valve 228, the check valve 228 opens by pressing the spring 235, sucks external air into the ink cartridge 220, and then closes. Thus, the negative pressure in the ink cartridge 220 is kept constant.

The ink cartridge 220 shown in FIG.
B shows the first storage chamber 225 instead of providing the check valve 228 in the ink cartridge 220A of FIG.
The porous member 242 is arranged at a. Porous member 24
2 holds the ink in the ink cartridge 220B and prevents the ink from leaking out of the ink cartridge 220B when the ink cartridge 220B sways.

The case where the actuator 106 is mounted on the ink cartridge or the carriage in the ink cartridge that is mounted on the carriage and separate from the carriage has been described. The actuator 106 may be mounted on the ink tank to be used. Furthermore, through a tube or the like separate from the carriage,
The actuator 106 may be mounted on an off-carriage type ink tank that supplies ink to the carriage.
Further, the actuator of the present invention may be mounted on an ink cartridge in which the recording head and the ink container are integrally exchangeable.

[Structure and Advantages of Mounting Module with Cavity] The various ink cartridges having the ink consumption detecting function according to the present embodiment have been described above.
In these ink cartridges, ink consumption was detected using a piezoelectric device. Among these configurations, an actuator which is a piezoelectric device was shown. And the mounting module body which integrated the piezoelectric device and the mounting member was shown. A representative example is shown in FIG. 32, for example. As described above, by using the mounting module, the piezoelectric device can be protected. Further, the use of the mounting module facilitates the mounting of the piezoelectric device.

In this embodiment, a mounting module with a cavity is particularly shown. The mounting module of this type has the following advantages.

(1) Referring again to FIG. 32 and FIG. FIG. 32 shows the mounting module 100 in an assembled state, and FIG. 33 shows the mounting module 100 in an exploded state. The actuator 106 (piezoelectric device) and the mounting member are integrated. The mounting module 100 is mounted on the ink cartridge.

A through hole 112 is provided in the plate 110 which is a part of the mounting member. The through-hole 112 corresponds to the opening cavity of the present invention (hereinafter, the through-hole 112 is appropriately referred to as an opening cavity). The through hole 112 faces the actuator 106 and is located at a position facing the inside of the ink cartridge from the actuator 106. Vibration is transmitted between the piezoelectric device and the inside of the container via the cavity 112.

As the consumption of ink progresses, the liquid level decreases, and the through-hole 112 is exposed. At this time, a substantially constant amount of ink remains in the through hole 112 and is held. The amount of retained ink is determined by the shape and installation angle of the through-hole 112, the viscosity of the ink, and the like. The acoustic impedance corresponding to this fixed amount of ink can be obtained in advance by measurement or the like. Depending on whether such acoustic impedance is detected, it is possible to reliably stop ink consumption.

As described above, to detect ink consumption,
The residual vibration state of the piezoelectric device can be used. The piezoelectric device enters a residual vibration state after oscillation. The residual vibration state, especially its resonance frequency, corresponds to the change in acoustic impedance and the ink consumption state. Ink consumption can be reliably detected by detecting whether or not a residual vibration state when a small amount of ink is held in the through hole 112 is detected.

According to the present embodiment, as described above, by providing the cavity (through-hole), it is possible to prevent erroneous detection due to ink undulation or the like. This is because since the ink is originally attached to the cavity, there is no presence or absence of ink due to waving or the like, and the detection result is hardly influenced by such ink attachment.

Further, by providing the cavity, the distance between the actuator 106 and the ink is reduced. Actuator 106 without intervening plate 110
Vibration is transmitted between the ink and the ink. Here, only a small amount of ink near the piezoelectric device mainly affects the residual vibration of the piezoelectric device. This small amount of ink exists near the piezoelectric device due to the provision of the cavity, and is in contact with the piezoelectric device. Thereby, the change in the residual vibration due to the consumption of the ink becomes remarkable, so that the consumption of the ink can be reliably detected.

The cavity does not have to penetrate the plate 110. In this case, a cavity is formed by the concave portion of the plate 110.

Further, in the present embodiment, the cavity is provided locally, and the sealing properties of the ink are ensured by the surrounding members. The actuator 106, especially the piezoelectric element thereof, is effectively protected from the conductive ink.

Here, detection of ink consumption based on acoustic impedance, particularly detection using residual vibration, has been described.
However, ink consumption may be detected using an actuator and utilizing elastic waves and reflected waves. The time until the reflected wave returns may be obtained. Other principles may be applied. The same applies to the following description.

(2) The shape of the cavity is a shape that holds ink in a predetermined liquid state. The cavity shape is set so that the ink can be held even in the detection target ink consumption state. By using the residual vibration corresponding to the ink amount at this time as a reference, it is possible to accurately detect whether or not the ink has been consumed.

[0230] Here, it is considered that if ink does not remain in the cavity, it is originally easier to detect ink consumption. However, the problem of ink adhesion as described above may occur. If ink remains or does not remain in the cavity, that is, if there is a variation in the remaining ink state, it is possible that this variation may cause a detection error. In such a case, it is preferable that the cavity holds the ink as described above. In order to achieve this, for example, the cavity only needs to have a predetermined depth that can prevent all of the ink from flowing out. In this embodiment, since the plate of the module body has an appropriate thickness, the cavity is also provided with a necessary depth.

(3) The actuator 106 (piezoelectric device) of the module 100 has a piezoelectric element. The piezoelectric element includes a piezoelectric layer, an upper electrode, and a lower electrode (see FIG. 20). A lower electrode is formed on a substrate, a piezoelectric layer is formed thereon, and an upper electrode is formed thereon. As one feature of the present embodiment, the area of the cavity is set to be larger than the area of the lower electrode.
More specifically, the area of the opening cavity on the piezoelectric element side is
It is set to be equal to or larger than the area of the overlapping portion between the piezoelectric layer and the lower electrode. This has the following advantages.

The lower electrode of the piezoelectric element is closest to the cavity and smallest. The piezoelectric element vibrates in the range covered by the lower electrode. The size of the vibrating region is substantially equal to the size of the lower electrode. The vibration characteristics of the piezoelectric element can be adjusted by the size of the lower electrode. In the present embodiment, the cavity shape is set so as to correspond to the lower electrode. That is, the area of the cavity is set to be larger than that of the lower electrode. Thereby, the piezoelectric element can vibrate in an appropriate state.

(4) Next, the appropriate relationship between the cavity depth and the cavity opening size will be further described. FIG.
In the above, the cavity depth is a cavity dimension of the module body 100 in the central axis direction. In FIG. 33, since the cavity 112 penetrates the plate 110, the cavity depth is equal to the plate thickness. On the other hand, the cavity opening dimension is a dimension perpendicular to the cavity depth, and is the size of the opening on the plate.

In the present embodiment, the depth of the cavity 112 is set smaller than the opening size. In short, the cavity 112 has a shallow and wide shape. This allows
The following advantages are obtained.

Since the cavity is shallow and wide, the amount of ink remaining in the cavity when the amount of ink decreases is reduced. Therefore, the change in the residual vibration depending on whether or not the ink has been consumed becomes large, and the detection accuracy can be improved.

If the cavity has a deep and narrow shape, vibration may not be properly transmitted from the cavity into the container. On the other hand, according to the present embodiment, since the cavity is shallow and wide, good vibration transmission can be obtained in detecting a change in residual vibration.

According to the study of the present inventor, it is preferable that the cavity depth is equal to or less than 1/3 of the opening size, whereby a change in the residual vibration also appears remarkably.

In the above description, a circular cavity is mainly considered. However, within the scope of the present invention, the cavity may have various shapes. In consideration of such a shape of the cavity, in the present invention, the cavity depth may be set to be smaller than the minimum width of the cavity opening. Preferably, the cavity depth is not more than 1/3 of the minimum width of the cavity opening. For example, when the cavity has a rectangular shape, the dimension of the short side is set to be larger than the cavity depth.

(5) Further, as one feature of the present embodiment, the opening cavity has a shape substantially symmetric with respect to the center of vibration of the liquid detecting device (the center of the piezoelectric element). Preferably the cavity is circular.

According to this configuration, a detection characteristic in which a single peak appears in the low order can be obtained. In the piezoelectric film, the primary vibration mode becomes dominant, and the S / N ratio increases. The amplitude of the back electromotive force also increases. Therefore, the detectability is good.

Further, by adopting the isotropic shape, the influence of the fixing portion such as the adhesive on the detection accuracy can be reduced. For example, consider fixing using an epoxy adhesive. This type of adhesive shrinks during curing. For this reason, if the shape of the cavity is not symmetric, distortion occurs due to the influence of shrinkage and the like, so that the vibration characteristics vary depending on locations around the cavity. On the other hand, in the present embodiment, the cavity shape is symmetric. For this reason, even if an adhesive is used for fixing the plate, the plate is hardly affected by distortion, so that uniform vibration characteristics can be obtained all around the cavity. As shown in this example, according to the present embodiment, the influence of the fixing structure can be reduced, so that the mountability can be improved. A relatively simple mounting method can also be adopted. Then, the manufacture of the piezoelectric device and the ink cartridge is facilitated.

In particular, according to the present embodiment, high uniformity can be obtained by making the cavity circular. Since the detectability is improved, the advantages of the present embodiment described above can be more remarkably obtained. Also, by adopting a circular shape,
A cavity can be formed by punching with a punch, etc.
Another advantage is that it is easy to manufacture.

(6) The mounting module body 100 and the piezoelectric device (actuator 106) are installed at liquid level positions corresponding to a predetermined liquid consumption state as a detection target. When the liquid surface passes through the piezoelectric device, the ink remains in the cavity and is held. At this time, the mounting module, particularly the cavity shape, is configured to generate a detection signal indicating a residual vibration state corresponding to the liquid in the open cavity.

As described above, the cavity depth t and the cavity opening radius a satisfy the condition (a / t)> (3 × π / 8)
When the condition is satisfied (the cavity is substantially circular), the ink consumption can be detected with the ink remaining in the cavity.

(7) As a preferable application example of the present embodiment, the opening area (dimension) of the cavity inside the container is:
It is set larger than the opening area (dimension) on the actuator (piezoelectric device) side. This gives the cavity a shape that extends toward the interior of the container. According to this configuration, unnecessary ink can be effectively prevented from remaining in the cavity portion, and thus the detection capability can be improved.

Referring to FIG. 47 (a) and FIG. 47 (b). FIG. 47A shows a cavity having a tapered shape. FIG. 47B shows a cavity having a step shape. Both cavities extend toward the interior of the ink container. According to these cavity shapes, unnecessary ink hardly remains around the cavity when the ink is consumed. That is, only a substantially constant amount of ink remains in the cavity, which enables highly reliable detection and improves detection accuracy. On the other hand, if the cavity does not have a tapered shape or a stepped shape, unnecessary ink may remain around the cavity due to the influence of surface tension or the like. In this case, the amount of ink held in the cavity varies. Variations in the holding amount cause uncertain detection. According to the present embodiment, such a situation can be avoided and ink consumption can be reliably detected.

(8) As a preferred application of the present embodiment, a communication groove communicating with the cavity is provided at a location facing the inside of the cartridge so as to extend from the cavity. An example of the communication groove is shown in FIG. The communication groove G starts from the cavity 112 and the plate 110
Has continued halfway through. By providing the communication groove G,
The ink in the cavity easily flows out, and the amount of ink remaining in the cavity is reduced. The amount of unnecessary ink remaining near the cavity due to the influence of surface tension can be effectively reduced. This stabilizes the ink holding amount. Since the change in the residual vibration depending on whether the liquid surface has passed through the cavity, that is, whether or not the ink has been consumed, becomes more remarkable, the ink consumption can be detected more reliably, and the detection accuracy can be improved. It is desirable to form the communication groove so that more ink flows out of the cavity. Preferably, the communication groove is provided toward a supply port of the ink cartridge. The communication groove extends along a direction from the cavity to the supply port. Thereby, the ink in the cavity can be smoothly guided to the supply port.

(9) As one of the features of this embodiment,
The mounting member of the module is fitted into a through hole provided in the ink cartridge. Referring to FIG. 49, FIG.
A second module 100 is mounted in a through hole in the cartridge wall. The holes of the body and the wall of the module 100 have the same shape, and the module 100 is fitted in the through-hole without any gap. Further, the module 100
The seal is ensured by the flange at the end of. By employing such a structure, the module body can be easily assembled, and the sensor unit with the cavity can be arranged at an appropriate position.

(10) In this embodiment, the piezoelectric device (actuator) is provided with a concave portion communicating with the opening cavity of the mounting member. The recess is a through hole provided in the substrate of the actuator, and functions as (part of) the open cavity. With such a configuration, the opening cavity approaches the vibrating portion of the piezoelectric device (see FIG. 38).

(11) In a preferred embodiment, the open cavity is provided in proximity to a liquid absorber for sucking ink in the cavity. The liquid absorber is, for example, a porous member,
In short, it is composed of a member such as a sponge.

FIGS. 50A and 50B show an example of a structure in which the cavity 800 and the absorber 802 are close to each other. In the former, the absorber 802 has the cavity 800
Directly facing. In the latter, the cavity 800
The absorber 802 faces a communication groove G extending from the absorber.

With this configuration, unnecessary ink can be sucked out of the cavity. It is possible to prevent the ink remaining state from becoming unstable due to the influence of surface tension or the like.
That is, the variation in the amount of ink held in the cavity is reduced. The cavity may be completely depleted of ink. Since the detection error caused by the variation in the ink holding amount is reduced, the detection accuracy can be improved.

(12) In another preferred embodiment, a liquid absorber for holding a liquid is provided in the open cavity. That is, the absorber is arranged inside the cavity, not outside the cavity. Also here, the liquid absorber is formed of, for example, a porous member, that is, a member such as a sponge. FIG. 51 shows an example of a configuration in which an absorber 804 is provided in a cavity 800.

In this configuration, ink is positively held in the cavity. The amount of ink retained depends on the structure and shape of the absorber. When the absorber fills the cavity as shown, the amount of ink retained is determined by the shape of the cavity. Also according to this mode, the variation in the amount of retained ink in the cavity is reduced. Since the detection error caused by the variation in the ink holding amount is reduced, the detection accuracy can be improved.

(13) Preferably, the attachment module is detachably attached to the ink cartridge. Since the sensor may be mounted on the ink cartridge in the form of a mounting module, the mounting of the sensor is easy. By removing the mounting module, the sensor can be taken, so that the ink cartridge can be easily recycled.

As described above, the present invention has been described using the embodiments. However, the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be added to the above embodiment. It should be noted that such modified or improved embodiments may be included in the technical scope of the present invention.
It is clear from the description of the claims.

For example, the liquid container is not limited to an ink cartridge. The present invention may be applied to a printer ink tank other than an ink cartridge. Further, the present invention may be applied to a container containing a liquid other than ink.

The piezoelectric device does not have to generate vibration by itself. That is, the oscillation, the output of the residual vibration state,
It is not necessary to perform both. For example, the vibration state of the piezoelectric device is detected after another actuator generates vibration. Alternatively, when the piezoelectric device vibrates due to vibration generated in the ink cartridge due to movement of the carriage or the like, the vibration is detected. That is, the ink consumption is detected using the vibration naturally generated by the printer operation without actively generating the vibration. On the other hand, contrary to the above modification, the piezoelectric device may only generate vibration. In this case, the vibration state of another sensor or the like is required.

The above modification can be similarly applied to another detection function using a piezoelectric device, for example, a detection function using an elastic wave and a reflected wave. That is, the piezoelectric device may be used for either generation or detection of vibration.

[0260]

As described above, according to the present invention, by providing an opening cavity in a mounting module body for mounting a piezoelectric device to a liquid container, it is possible to improve the ability to detect a liquid consumption state. Become.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of an ink cartridge for a single color, for example, a black ink.

FIG. 2 is a diagram illustrating an embodiment of an ink cartridge that stores a plurality of types of ink.

FIG. 3 is a diagram showing an embodiment of an ink jet recording apparatus suitable for the ink cartridge shown in FIGS. 1 and 2.

FIG. 4 is a view showing a detailed cross section of the sub tank unit 33.

FIG. 5 is a diagram showing a method of manufacturing the elastic wave generating means 3, 15, 16, and 17;

FIG. 6 is a view showing another embodiment of the elastic wave generating means 3 shown in FIG.

FIG. 7 is a view showing another embodiment of the ink cartridge of the present invention.

FIG. 8 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 9 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 10 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 11 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 12 is a view showing another embodiment of the ink cartridge shown in FIG. 11;

FIG. 13 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 14 is a diagram showing a plane view of still another embodiment of the through hole 1c.

FIG. 15 is a diagram showing a cross section of an embodiment of the ink jet recording apparatus of the present invention.

FIG. 16 is a diagram showing an embodiment of an ink cartridge suitable for the recording apparatus shown in FIG.

FIG. 17 is a view showing another embodiment of the ink cartridge 272 of the present invention.

FIG. 18 is a diagram showing still another embodiment of the ink cartridge 272 and the ink jet recording apparatus of the present invention.

FIG. 19 is a view showing another embodiment of the ink cartridge 272 shown in FIG.

20 is a diagram showing details of an actuator 106. FIG.

FIG. 21 is a diagram showing the periphery of an actuator 106 and its equivalent circuit.

FIG. 22 is a diagram illustrating a relationship between ink density and a resonance frequency of ink detected by an actuator 106.

FIG. 23 is a diagram showing a back electromotive force waveform of the actuator 106.

FIG. 24 is a view showing another embodiment of the actuator 106.

25 is a diagram showing a cross section of a part of the actuator 106 shown in FIG. 24.

26 is a diagram showing a cross section of the entire actuator 106 shown in FIG. 25.

FIG. 27 is a diagram illustrating a method of manufacturing the actuator 106 illustrated in FIG. 24.

FIG. 28 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 29 is a view showing another embodiment of the through hole 1c.

FIG. 30 is a view showing another embodiment of the actuator 660.

FIG. 31 is a view showing still another embodiment of the actuator 670.

32 is a perspective view showing the module 100. FIG.

FIG. 33 is an exploded view showing a configuration of the module 100 shown in FIG. 32.

FIG. 34 is a view showing another embodiment of the module body 100.

FIG. 35 is an exploded view showing a configuration of the module 100 shown in FIG. 34.

FIG. 36 is a view showing still another embodiment of the module body 100.

FIG. 37 is a diagram showing an example of a cross section in which the module body 100 shown in FIG. 32 is mounted on an ink container 1.

FIG. 38 is a view showing still another embodiment of the module body 100.

39 is a diagram showing an embodiment of an ink cartridge and an ink jet recording apparatus using the actuator shown in FIGS. 20 and 21. FIG.

FIG. 40 is a diagram illustrating details of an inkjet recording apparatus.

FIG. 41 is a view illustrating another embodiment of the ink cartridge 180 illustrated in FIG. 40;

FIG. 42 is a view showing still another embodiment of the ink cartridge 180.

FIG. 43 is a view showing still another embodiment of the ink cartridge 180.

FIG. 44 is a view showing still another embodiment of the ink cartridge 180.

FIG. 45 is an ink cartridge 1 shown in FIG.
FIG. 28 illustrates another embodiment of the present invention.

FIG. 46 is a view showing still another embodiment of the ink cartridge using the module body 100.

FIG. 47 is a diagram showing advantages obtained by forming the opening cavity in a tapered shape and a stepped shape.

FIG. 48 is a diagram showing an example of a communication groove preferably provided around a cavity.

FIG. 49 is a diagram illustrating an example of a configuration in which a module is fitted into a through hole of an ink cartridge.

FIG. 50 is a diagram illustrating an example of a configuration in which a cavity is provided near an absorber.

FIG. 51 is a diagram illustrating an example of a configuration in which an absorber is provided in a cavity.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Ink supply port 100 Module 102 Base part case 104 Lead wire 106 Actuator 108 Film 110 Plate 112 Cavity 113 Concave part 114 Opening 116 Cylindrical part G Communication groove K Ink

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) H01L 41/09 H01L 41/08 U 41/187 C 41/18 101D (72) Inventor Minoru Usui 3 Yamato 3 Suwa City, Nagano Prefecture No. 3-5 Seiko Epson Corporation F-term (reference) 2C056 EA29 EB20 EB51 KC05 KC30 KD06 2F013 BF00 BG12 CB10 2F014 AA01 AA07 AB01 AB02 AB03 CB01 FB01

Claims (20)

[Claims] 1. A piezoelectric device used to detect a consumption state of a liquid in a liquid container, and an attachment member integrated with the piezoelectric device and attaching the piezoelectric device to the liquid container, The mounting module for liquid detection, wherein the mounting member has an opening cavity communicating with the inside of the liquid container at a position facing the piezoelectric device. 2. The mounting module for detecting a liquid according to claim 1, wherein the piezoelectric device detects a liquid consumption state based on a change in acoustic impedance. 3. The liquid crystal device according to claim 2, wherein the piezoelectric device outputs a signal indicating a residual vibration state, and the liquid consumption state is detected based on a change in the residual vibration state according to the liquid consumption state. 3. A mounting module for liquid detection according to claim 1. 4. The mounting module for detecting a liquid according to claim 1, wherein the opening cavity is shaped to hold a liquid in a predetermined liquid state. 5. The piezoelectric device includes a lower electrode, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer, wherein the area of the open cavity is equal to the area of the piezoelectric layer. 2. The mounting module for liquid detection according to claim 1, wherein the size is set to be equal to or greater than the area of the overlapping portion of the lower electrode. 6. The mounting module according to claim 1, wherein the cavity depth of the opening cavity is set to be smaller than a minimum width of the cavity opening. 7. The mounting module for detecting liquid according to claim 6, wherein the depth of the cavity is equal to or less than 1/3 of a minimum width of the cavity opening. 8. The mounting module according to claim 1, wherein the opening cavity has a shape substantially symmetric with respect to a center of a vibrating portion of the piezoelectric device. 9. The mounting module for detecting liquid according to claim 8, wherein the opening shape of the opening cavity is circular. 10. A cavity depth t and a cavity opening radius a of the opening cavity satisfy a condition (a / t)> (3 ×
The mounting module body for liquid detection according to claim 9, wherein (π / 8) is satisfied. 11. The mounting module for liquid detection according to claim 1, wherein an opening area of the opening cavity on the container inner side is larger than an opening area of the piezoelectric device side. 12. The mounting module according to claim 11, wherein a peripheral surface of the opening cavity has a tapered shape. 13. The mounting module for detecting a liquid according to claim 11, wherein a peripheral surface of the opening cavity has a step shape. 14. The liquid supply apparatus according to claim 1, wherein the mounting member is fitted into a through hole provided in the liquid container.
14. The mounting module for detecting a liquid according to any one of 13). 15. The mounting module for detecting a liquid according to claim 1, wherein the piezoelectric device has a concave portion communicating with the opening cavity of the mounting member. 16. The mounting module for detecting a liquid according to claim 1, wherein a liquid absorber is provided near the opening cavity. 17. The mounting module for detecting a liquid according to claim 1, wherein a liquid absorber is provided in the opening cavity. 18. The mounting module for detecting a liquid according to claim 1, wherein the mounting module is detachably attached to the liquid container. 19. A liquid container provided with the mounting module for liquid detection according to claim 1. Description: 20. An ink cartridge to be mounted on an ink jet recording apparatus provided with the mounting module for liquid detection according to claim 1. Description: