JP2002154223A - Liquid consumption state detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid consumption state detector capable of avoiding wrong detection of the liquid residual amount in the case influence of a noise exists. SOLUTION: This liquid consumption state detector comprises an oscillating part with at least a part exposed in a storage space for storing a liquid, capable of oscillating the storage space, and a piezoelectric element capable of oscillating the oscillating part based on a driving signal and generating a counter electromotive force by the oscillation of the oscillating part. Liquid consumption state detecting parts 1200, 1202, 1210 detect the liquid consumption state based on the counter electromotive force signal from the piezoelectric element. The liquid consumption state detecting parts 1200, 1202, 1210 comprise a noise influence judging part 880 for judging the influence of a noise to the counter electromotive force signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid consumption state detection method capable of detecting a consumption state of a liquid such as ink by detecting a change in acoustic impedance, in particular, by detecting a change in a resonance frequency. It is about a vessel.

[0002]

2. Description of the Related Art In an ink jet recording apparatus, an ink jet recording head having pressure generating means for pressurizing a pressure generating chamber and nozzle openings for discharging pressurized ink as ink droplets is mounted on a carriage. .

An ink jet recording apparatus is configured to be able to continue printing by continuously supplying ink in an ink tank to a recording head via a flow path. The ink tank is configured as a detachable cartridge that can be easily replaced by a user when ink is consumed, for example.

Conventionally, as a method of managing ink consumption of an ink cartridge, a method of integrating the number of ink droplets ejected from a recording head and the amount of ink sucked by maintenance by software to manage the ink consumption by calculation, There is a method of attaching a liquid level detection electrode to an ink cartridge to manage a point in time when a predetermined amount of ink is actually consumed.

[0005] However, the following problem arises in the method of calculating the ink consumption by calculating the number of ejected ink droplets and the amount of ink by software and calculating the ink consumption. Some heads have a variation in the weight of the ejected ink droplets. Although the image quality is not affected, the ink cartridge is filled with a margin in consideration of the accumulated case.
Therefore, there is a problem that the ink remains for the margin depending on the individual. On the other hand, the method of managing the time when ink is consumed by the electrode can detect the actual amount of ink. Therefore, the remaining ink amount can be managed with high reliability.
However, since the detection of the liquid level of the ink depends on the conductivity of the ink, the types of ink that can be detected are limited, and the sealing structure of the electrodes may be complicated. In addition, as a material of the electrode, a noble metal having high conductivity and high corrosion resistance is usually used, so that the manufacturing cost of the ink cartridge increases. Furthermore, since it is necessary to mount two electrodes, the number of manufacturing steps increases, and as a result, manufacturing costs increase.

[0006]

Problems to be Solved by the Invention Japanese Patent Application No. 2000-147
No. 052 discloses a piezoelectric device and a module mounted on a liquid container that can accurately detect the remaining amount of liquid and eliminate the need for a complicated sealing structure in order to solve the above-mentioned problem. Japanese Patent Application No. 2000-146966 discloses a detection control circuit that can be used for such a piezoelectric device and a module.

The inventor of the present invention has found that when there is an influence of noise, the detection control circuit according to Japanese Patent Application No. 2000-146966 erroneously detects the remaining amount of liquid.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a liquid consumption state detector capable of avoiding erroneous detection of the remaining amount of liquid when there is an influence of noise. The purpose is to provide.

[0009]

According to the present invention, at least a part is exposed to a storage space for storing a liquid, and a vibration part capable of vibrating with respect to the storage space is provided. And a piezoelectric element that generates a back electromotive force signal by the vibration of the vibrating part,
A liquid consumption state detection unit that detects a liquid consumption state based on a back electromotive force signal from the piezoelectric element, wherein the liquid consumption state detection unit includes a noise influence determination unit that determines an influence of noise on the back electromotive force signal. It is a liquid consumption state detector characterized by having.

According to the present invention, since the influence of noise on the back electromotive force signal is determined by the noise influence determination unit, for example, when it is difficult to accurately detect the liquid consumption state due to the presence of noise, the detection of the liquid consumption state is performed. Can be stopped.

The liquid consumption state detector measures, for example, the frequency of the back electromotive force signal. Since the frequency of the back electromotive force signal corresponds to the resonance frequency of the substance in the accommodation space, the liquid consumption state can be easily and accurately detected.

Specifically, the liquid consumption state detecting section has a counter for measuring the number of vibrations of the back electromotive force signal for a predetermined time, and based on the numerical value measured by the counter, the back electromotive force signal is detected. Is measured.

Alternatively, the liquid consumption state detection unit has a clock counter for measuring a time during which the back electromotive force signal vibrates a predetermined number of times, and based on the time measured by the clock counter, The frequency of the back electromotive force signal is measured.

Preferably, the liquid consumption state detection unit cannot detect the liquid consumption state when the noise influence determination unit determines that the influence of the noise on the back electromotive force signal exceeds a predetermined level. Is output.

According to an example of a preferred circuit configuration, the liquid consumption state detecting section includes a voltage generating section for generating a first reference voltage, a second reference voltage higher than the first reference voltage, and a counter electromotive force signal. An amplification unit for amplifying the first reference voltage as a center;
The signal amplified by the amplification unit is Hi with respect to the second reference voltage.
and a comparing unit for comparing whether the output is gh or Low, and the noise influence determining unit determines whether the output of the comparing unit is constant at Low in a state before the vibrating unit is vibrated based on the drive signal. If the output of the comparing unit is not constant, it is determined that the influence of noise is small.

Alternatively, the liquid consumption state detecting section includes a voltage generating section for generating a first reference voltage, a second reference voltage lower than the first reference voltage, and a counter electromotive force signal centered on the first reference voltage. An amplification unit for amplifying, and a comparison unit for comparing whether the signal amplified by the amplification unit is High or Low with respect to the second reference voltage.
In a state before the vibrating section is vibrated based on the drive signal, if the output of the comparing section is constant at High, it is determined that the influence of noise is small. If the output of the comparing section is not constant, the influence of noise is large. It is determined.

In addition, preferably, a portion of the vibrating portion exposed to the liquid storage space has a symmetrical shape when viewed from the liquid storage space side. The piezoelectric element is preferably fixed at a position substantially at the center of a portion of the vibrating portion exposed to the liquid storage space, on a side opposite to the liquid storage space side of the vibration portion.

Particularly preferably, a portion of the vibrating portion exposed to the liquid accommodating space has a circular shape when viewed from the inner surface side of the liquid container.

Preferably, the vibration direction of the piezoelectric element is substantially perpendicular to a portion of the vibrating portion exposed to the liquid storage space.

The present invention also relates to a liquid container (for example, an ink cartridge) including a liquid consumption state detector having any of the above-described features and a wall for defining a storage space for storing the liquid. Is protected.

In this case, it is preferable that the liquid container further includes a storage unit for storing the liquid consumption state detected by the liquid consumption state detector.

Further, a liquid consuming apparatus (for example, an ink jet recording apparatus) comprising a liquid container having the above-described characteristics and a liquid consuming main body connected to the liquid container and consuming the liquid contained in the liquid container. ) Are also protected by this case.

In this case, the liquid consuming apparatus may further include a control circuit for controlling a liquid consuming operation in the liquid consuming main body based on the liquid consuming state of the liquid container detected by the liquid consuming state detecting unit. preferable.

Alternatively, when the liquid container has a storage unit for storing the liquid consumption state detected by the liquid consumption state detector, the liquid consuming device performs the operation based on the liquid consumption state of the liquid container stored by the storage unit. It is preferable to further include a control circuit unit that controls a liquid consuming operation in the liquid consuming main unit.

Further, there is provided a control device for controlling a liquid consumption state detector having any of the above features,
The present invention also provides a control device in which a drive signal is supplied to the piezoelectric element to cause the liquid consumption state detection unit to detect the liquid consumption state.

In this case, the control device causes the noise influence determination section to determine the influence of noise before giving the drive signal to the piezoelectric element, and when the influence of noise is determined to be small, the control signal is applied to the piezoelectric element. And it is preferable to cause the liquid consumption state detection unit to detect the liquid consumption state.

The control device or each element of the control device can be realized by a computer system.

Further, a program for causing a computer system to realize each device or each means and a computer-readable recording medium on which the program is recorded are also provided.
This is the subject of protection.

Here, the recording medium includes not only a floppy disk (registered trademark) or the like which can be recognized as a single unit, but also a network for transmitting various signals.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail through embodiments of the present invention. The following embodiments do not limit the claimed invention, and not all combinations of features described in the embodiments are necessarily essential for solving the invention.

The basic concept of the present invention is to utilize the vibration phenomenon to determine the state of the liquid in the liquid container (the presence or absence of the liquid in the liquid container, the amount of the liquid, the liquid level of the liquid, the type of the liquid, and the composition of the liquid). ).

As a specific method of detecting the state of the liquid in the liquid container using the vibration phenomenon, several methods can be considered. For example, a medium in the liquid container and a change in the state of the medium in the liquid container are detected by generating an elastic wave in the liquid container by the elastic wave generating means and receiving a reflected wave reflected by the liquid surface or an opposing wall. There is a way to do that. There is also 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. There is a method of detecting a change in acoustic impedance by detecting the frequency or the amplitude of the back electromotive force waveform.
Alternatively, the impedance characteristic or admittance characteristic of the liquid is measured by a measuring device, for example, an impedance analyzer such as a transmission circuit, and a change in a current value or a voltage value,
Alternatively, there is a method of measuring a change in a current value or a voltage value according to frequency when vibration is applied to a liquid.

Hereinafter, the operation principle of the piezoelectric device or the actuator will be described in detail. 1 and 2 show details and an equivalent circuit of an actuator 106 which is an embodiment of the piezoelectric device.

The actuator 106 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 change in acoustic impedance by detecting a resonance frequency based on residual vibration to detect a consumption state of a liquid in a liquid container.

FIG. 1A is an enlarged plan view of the actuator 106. FIG. 1B shows the state of the actuator 106.
3 shows a BB cross section of FIG. FIG. 1C shows an actuator 1
06 shows a CC section. 2 (A) and FIG.
(B) shows an equivalent circuit of the actuator 106. FIGS. 2C and 2D show the periphery including the actuator 106 when the ink cartridge is filled with ink and the equivalent circuit thereof, respectively.
(E) and FIG. 2 (F) respectively show 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 disposed 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.
Auxiliary electrode 172 disposed between and electrically couples the two.
And

The piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 each have a circular portion as a main portion. 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.

The cavity 162 is formed by a portion of the vibration plate 176 facing the opening 161 and the opening 161 of the substrate 178. The surface of the substrate 178 opposite to the piezoelectric element (hereinafter referred to as the back surface) faces the inside of the liquid container.
Thereby, 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 the liquid does not leak to the surface side of the substrate 178 even if the liquid enters the cavity 162.

The lower electrode 166 is located on the surface of the vibration plate 176 (the surface opposite to the liquid container). The lower electrode 166 is attached such that the center of the circular portion, which is the main part, and the center of the opening 161 substantially coincide with each other. Note that 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, on the surface side of the lower electrode 166, the piezoelectric layer 160 is arranged (formed) such that the center of the circular portion and the center of the opening 161 substantially coincide with each other. In this case, the area of the circular portion of the piezoelectric layer 160 is set to be smaller than the area of the opening 161 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
It is arranged (formed) so that the center of 61 substantially matches. The area of the circular portion of the upper electrode 164 is
In addition, it is set to be smaller than the area of the circular portion of the piezoelectric layer 160 and larger than the area of the circular portion of the lower electrode 166.

Therefore, the main part of the piezoelectric layer 160 is sandwiched between 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. Accordingly, the piezoelectric layer 160 can be effectively deformed and driven. A circular portion, which is a main portion of each of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166,
The piezoelectric element in the actuator 106 is formed.

As described above, such a piezoelectric element is in contact with the vibration plate 176. The opening 161 has the largest area among 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. Due to such a structure, the diaphragm 17
The vibration area of 6 that actually vibrates is determined by the opening 161.

Further, since the area of each of the circular portion of the upper electrode 164, the circular portion of the piezoelectric layer 160, and the circular portion of the lower electrode 166 is smaller than the area of the opening 161, the vibration plate 176 is more likely to vibrate. .

Further, of the circular portion of the lower electrode 166 and the circular portion of the upper electrode 164 electrically connected to the piezoelectric layer 160, 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 that generates the piezoelectric effect.

The centers of the circular portions of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 forming the piezoelectric element substantially coincide with the centers of the openings 161. Further, a circular opening 161 for determining a vibrating portion of the diaphragm 176 is provided.
Is located substantially at the center of the entire actuator 106. Therefore, the center of the vibrating part of the actuator 106 substantially coincides with the center of the actuator.

Further, since the main part of the piezoelectric element and the vibrating part of the vibration plate 176 have circular shapes, the vibrating part of the actuator 106 is symmetrical with respect to the center of the actuator 106.

Since the vibrating portion has a symmetrical shape with respect to the center of the actuator 106, unnecessary vibration which may be caused by the asymmetry of the structure is not excited. For this reason, the detection accuracy of the resonance frequency is improved.

Further, since the vibrating portion has a shape symmetrical with respect to the center of the actuator 106, manufacturing is easy, and variation in shape among the piezoelectric elements can be reduced. Therefore, the variation of the resonance frequency for each piezoelectric element is reduced.

Since the vibrating portion has an isotropic shape,
It is less susceptible to variations in fixing during bonding, and can be uniformly bonded to the liquid container. That is, the actuator 1
06 is easy to mount on a liquid container.

Further, since the vibrating portion of the vibration plate 176 has a circular shape, a low-order, for example, first-order resonance mode becomes dominant in the resonance mode of the residual vibration of the piezoelectric layer 160. That is, a single peak appears in the resonance mode of the residual vibration. Therefore, the peak and the noise can be clearly distinguished, and the resonance frequency can be clearly detected.

Also, by increasing the area of the vibrating portion of the circular diaphragm 176, the difference between the amplitude of the back electromotive force waveform and the amplitude of the resonance frequency due to the presence or absence of liquid increases, and the accuracy of the resonance frequency detection is improved. It can be further improved.

The displacement of the vibration plate 176 due to the vibration is
It is much larger than the displacement due to 78 vibrations. That is, the actuator 106 has a two-layer structure of a substrate 178 having a small compliance (it is hard to be displaced by vibration) and a vibration plate 176 having a large compliance (it is easy to be displaced by vibration). With this two-layer structure, the displacement of the diaphragm 176 can be increased while being securely fixed to the liquid container by the substrate 178. For this reason, the difference between the amplitude of the back electromotive force waveform and the amplitude of the resonance frequency due to the presence or absence of liquid increases, and the accuracy of detection of the resonance frequency can be improved.

Further, since the compliance of the diaphragm 176 is large, the attenuation of the vibration is reduced, and the accuracy of detecting the resonance frequency can be improved.

The node of the vibration of the actuator 106 is located at the outer periphery of the cavity 162, that is, at the opening 16.
1 is located near the edge.

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, lower electrode terminal 170 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 piezoelectric layer 16
It is necessary to have a step equal to the sum of the thickness of 0 and the thickness of the lower electrode 166. It is difficult to form this step only with the upper electrode 164. Even if it is possible to form a step only by the upper electrode 164,
4 and the upper electrode terminal 168 may be weakly connected and may be disconnected. Therefore, the auxiliary electrode 17
The upper electrode 164 and the upper electrode terminal 168 are connected by using 2 as an auxiliary member. By doing so, both the piezoelectric layer 160 and the upper electrode 164 have a structure supported by the auxiliary electrode 172, and a desired mechanical strength can be obtained. In addition, the connection between the upper electrode 164 and the upper electrode terminal 168 can be established. It is possible to make sure.

It should be noted that the piezoelectric element and the vibrating region of the diaphragm 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,
The handling of the actuator 106 is facilitated.

Further, by increasing the strength of the substrate 178, the vibration characteristics can be improved. 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. In order to prevent portions other than the vibrating portion of the actuator 106 from vibrating, it is effective to make the piezoelectric element of the actuator 106 thinner and smaller and to make the diaphragm 176 thinner, in addition to increasing the strength of the substrate 178. is there.

As the material of the piezoelectric layer 160, lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), a lead-free piezoelectric film using no lead,
It is preferable to use As a material of the substrate 178,
It is preferable to use zirconia or alumina. Further, it is preferable to use the same material as the substrate 178 for the vibration plate 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. 1 and FIG.
Is mounted so as to come into 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, when the liquid in the liquid container is consumed and the liquid level falls below the mounting position of the actuator, no liquid exists in the cavity 162, or the liquid remains only in the cavity 162 and the liquid remains outside the cavity 162. Is in a state where gas is present.

The actuator 106 detects at least a difference in acoustic impedance due to the change in the state. Thereby, the actuator 106 is in a state where the liquid is sufficiently stored in the liquid container, or in a state where a certain amount or more of the liquid is consumed,
Can be detected. Further, the actuator 10
6 can also detect the type of liquid in the liquid container.

Here, the principle of liquid level detection by the actuator will be described. In order to detect a change in the acoustic impedance of the medium, an impedance characteristic or an admittance characteristic of the medium is measured. When measuring the impedance characteristic or the admittance characteristic, for example, a transmission circuit can be used. The transmission circuit applies a periodic voltage having a constant amplitude to the medium, changes the frequency, and measures a current flowing through the medium. Alternatively, the transmission circuit supplies a periodic current having a constant amplitude to the medium, and changes the frequency to measure the voltage of the medium. A change in the current value or the voltage value measured by the transmission circuit indicates a change in the 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 above method, the actuator 10
6 can detect a change in the acoustic impedance of the liquid using a change in the resonance frequency. The resonance frequency can be detected, for example, by measuring a back electromotive force caused by residual vibration remaining in the vibrating part after the vibrating part of the actuator vibrates. In this case, for example, the above-described piezoelectric element can be used.

The piezoelectric element generates a back electromotive force due to residual vibration remaining in the vibrating part of the actuator. The magnitude of the back electromotive force changes depending on the amplitude of the vibration part of the actuator. Therefore, the larger the amplitude of the vibrating part of the actuator, the easier the detection. In addition, 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. That is, the frequency of the vibrating portion 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 also includes various deformations such as bending and elongation, and thus has various frequencies including the resonance frequency fs. Therefore, the waveform of the back electromotive force when the piezoelectric element (vibrating portion) and the medium are in a resonance state is Fourier-transformed,
The resonance frequency fs is determined by specifying the most dominant frequency component.

The frequency fm when the admittance of the medium is maximum or the impedance is minimum is slightly different from the resonance frequency fs due to dielectric loss or mechanical loss of the medium. However, deriving the resonance frequency fs from the actually measured frequency fm is troublesome,
Generally, the frequency fm is used instead of the resonance frequency fs. Here, by inputting the output of the actuator 106 to the transmission circuit, the actuator 106 can detect at least the acoustic impedance.

A method of measuring the frequency fm by measuring the impedance characteristic or admittance characteristic of the medium, and a method of measuring the resonance frequency fs by measuring the back electromotive force generated by the residual vibration in the vibrating portion of the actuator. It has been experimentally proved that there is almost no difference between the resonance frequencies specified by.

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 stored in the liquid container, the liquid is filled in the cavity 162, and the vibration region is in contact with the liquid in the liquid container. On the other hand, when there is not enough liquid in the liquid container, the vibrating region comes into contact with the liquid remaining in the cavity in the liquid container, or does not come into contact with the liquid, but comes into contact with gas or vacuum.

A cavity 162 is provided in the actuator 106 of the present invention. Thus, the design can be made such that the liquid in the liquid container remains 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 106 to the liquid container, the liquid adheres to the vibration region 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 presence / absence of liquid is detected only from the presence / absence of liquid in the vibration region, the liquid adhering to the vibration region of the actuator hinders accurate detection of the presence / absence of liquid.

For example, when the liquid level is below the mounting position of the actuator, if the liquid container oscillates due to the reciprocating movement of the carriage and the like, the liquid wave and the liquid drops adhere to the vibration area. However, the actuator incorrectly determines that there is sufficient liquid in the liquid container.

Therefore, in the actuator 106, even if the liquid remains in the vibration area, the cavity is positively provided so as to accurately detect the presence or absence of the liquid. Even if the surface is wavy, 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. 2E, there is no liquid in the liquid container,
The case where the liquid remains in 62 is set as the threshold value of the presence or absence of the liquid. That is, there is no liquid around the cavity 162,
If there is less liquid in the cavity than this threshold, it is determined that there is no ink, and if there is liquid around the cavity 162, it is determined that there is ink if there is more liquid than this threshold.

For example, when the actuator 106 is mounted on the side wall of the liquid container, when the liquid in the liquid container is below the mounting position of the actuator, it is determined that there is no ink, and when the liquid in the liquid container is mounted on the mounting position of the actuator. If it is higher, it is determined that there is ink.

By setting the threshold value in this way,
Even when the ink in the cavity has dried and the ink has run out, it can be determined that there is no ink. Even if the ink again adheres to the cavity due to the shaking of the carriage or the like where the ink in the cavity runs out ( It can be determined that there is no ink (because the threshold is not exceeded).

Here, referring to FIGS. 1 and 2,
Medium and actuator 1 obtained by measuring back electromotive force
The operation and principle of detecting the state of the liquid in the liquid container from the resonance frequency with the vibrating part 06 will be described.

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. Therefore, an electric field is generated in a portion of the piezoelectric layer 160 that is interposed between the upper electrode 164 and the lower electrode 166. The piezoelectric layer 160 is deformed by this electric field. Piezoelectric layer 16
When 0 is deformed, the vibration area of the vibration plate 176 flexurally vibrates. For a while after the piezoelectric layer 160 is deformed, the flexural vibration remains in the vibrating part of the actuator 106.

The residual vibration is free vibration between the vibration part of the actuator 106 and the medium. Therefore, by setting the voltage applied to the piezoelectric layer 160 to a pulse waveform or a rectangular wave, it is possible to easily obtain a resonance state between the vibrating portion and the medium after the voltage is applied. The residual vibration is
The vibration of the vibrating portion 06 is accompanied by the deformation of the piezoelectric layer 160. Therefore, the piezoelectric layer 160 generates a back electromotive force. This 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. The resonance frequency can be specified by the detected back electromotive force. The state of the liquid in the liquid container can be detected based on the resonance frequency.

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. 1C is a sectional view of the actuator 106 when no ink remains in the cavity 162 in this embodiment. FIG. 2 (A) and FIG. 2 (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 the product of the product of the thickness of the vibrating portion and the density of the vibrating portion divided by the area of the vibrating portion. More specifically, as shown in FIG. ).

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, to be able to calculate Mact from the thickness, density and area of the entire vibrating part,
Although the respective areas of the piezoelectric layer 160, the upper electrode 164, the lower electrode 166, and the vibration area of the vibration plate 176 have the magnitude relationship as described above, it is preferable that the difference between the areas is small.

Further, in this embodiment, the piezoelectric layer 160,
In the upper electrode 164 and the lower electrode 166, it is preferable that a portion other than the circular portion, which is a main portion thereof, is so small as to be negligible relative to the main portion. Therefore,
In the actuator 106, Mact is the upper electrode 1
64, lower electrode 166, piezoelectric layer 160 and diaphragm 17
6 is the sum of the respective inertances of the vibration regions. In addition, the compliance Cact is the upper electrode 16
4. Lower electrode 166, piezoelectric layer 160 and diaphragm 176
Is the compliance of the portion formed by the vibrating region.

Note that FIG. 2A, FIG. 2B, FIG.
FIG. 2F shows an equivalent circuit of the vibrating portion of the actuator 106 and the cavity 162. In these equivalent circuits, Cact indicates compliance of the vibrating portion of the actuator 106. Cpzt, Celectrode1, Celect
rode2 and Cvib indicate the 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 / Cvib) (Equation 3) From Equations 2 and 3, FIG. It can also be expressed as

The compliance Cact represents the volume of the medium that can be accepted by deformation when pressure is applied to a unit area. That is, the compliance Cact indicates the ease of deformation.

FIG. 2C is a sectional view of the actuator 106 in a case where 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. 2C is the additional inertance (additional mass (influence on the vibration in the vibration area) when the liquid is sufficiently contained in the liquid container and the liquid is filled around the vibration area of the actuator 106. Divided by the square of the area). M′max is represented by M′max = (π × ρ / (2 × k ³ )) × (2 × (2 × k × a) ³ / (3 × π)) / (π × a ² ) ² (expression 4) (a is the radius of the vibrating part, ρ is the density of the medium, and k is the wave number.)

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

The wave number k is represented by the following equation: k = 2 × π × fact / c (Equation 5) (Fact is the resonance frequency of the vibrating part. C is the speed of sound propagating in the medium.) You.

FIG. 2D shows the actuator 1 in the case of FIG. 2C in which the liquid is sufficiently stored in the liquid container and the liquid is filled around the vibrating region of the actuator 106.
6 shows an equivalent circuit of a vibrating part 06 and a cavity 162.

FIG. 2E shows the case where 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. On the other hand, the additional inertance M ′ in a case where the liquid in the liquid container is consumed and the liquid around the vibration region of the actuator 106 is replaced with gas or vacuum while the liquid remains in the cavity 162 is generally , M ′ = ρ × t / S (Equation 6) (for more details, see Equation 8 described later). here,
t is the thickness of the medium involved in the vibration. S is the area of the vibration region of the actuator 106. When the vibration region is a circle having a radius a, S = π × a ² .

Accordingly, the additional inertance M ′ follows Expression 4 when the liquid is sufficiently contained in the liquid container and the liquid around the vibrating region of the actuator 106 is filled. On the other hand, when the liquid is consumed and the liquid around the vibration region of the actuator 106 is replaced with gas or vacuum while the liquid remains in the cavity 162,
According to Equation 6.

Here, as shown in FIG. 2E, 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 set to 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. 2F 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, parameters relating 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.
On the other hand, when the liquid is not sufficiently stored in the liquid container, the liquid remains in the cavity, or gas or vacuum comes into contact with the vibrating portion of the actuator 106. The liquid around the actuator 106 is consumed, and the additional inertance M′var in the process of shifting from M′max in FIG. 2C to M′cav in FIG. 2E depends on the state of the liquid in the liquid container. It changes as the density ρ of the medium and the thickness t of the medium change. Thereby, the resonance frequency fs also changes. Therefore, by specifying the resonance frequency fs, it is possible to detect the storage state (presence or absence) of the liquid in the liquid container.

Here, assuming that t = d as shown in FIG. 2 (E), if M′cav is expressed by using Equation 6, the depth d of the cavity is substituted for t in Equation 6, and M′cav is obtained. cav = ρ × d / S (Equation 7)

Further, if the medium is a liquid of a different type, the density ρ differs depending on the composition, so that the additional inertance M ′ and the resonance frequency fs are different. Therefore,
The type of liquid can be detected by specifying the resonance frequency fs.

FIG. 3A 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 as the remaining ink amount decreases.

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 a value represented by Expression 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 T in equation 6
Is the thickness of the medium involved in the vibration, so that d (see FIG. 1B) of the cavity 162 of the actuator 106 in which the liquid remains is made small, that is, by making the substrate 178 sufficiently thin, the ink gradually becomes thin. Can be detected (see FIG. 2 (C)). Here, tink is the thickness of the ink relating to the vibration, and tink-
max is assumed to be tink at M'max.

For example, the actuator 106 is disposed on the bottom surface of the ink cartridge substantially horizontally with respect to the ink level. In this case, when the ink is consumed and the liquid level of the ink becomes equal to or lower than the height of tink-max from the actuator 106, M′var gradually changes according to Expression 6, and the resonance frequency fs gradually changes according to Expression 1. Therefore, as long as the ink level is within the range of t, the actuator 106 can gradually detect the ink consumption state.

Alternatively, on the side wall of the ink cartridge,
The actuator 106 can be arranged substantially perpendicular to the ink level. In this case, when the ink is consumed and the ink level reaches the vibration area of the actuator 106,
As the water level decreases, the added inertance M ′ decreases. Thereby, the resonance frequency fs is gradually increased according to the equation (1). Therefore, the ink level is equal to the diameter 2 of the cavity 162.
a (see FIG. 2C), the actuator 106 can gradually detect the ink consumption state.

The curve X in FIG. 3A shows the case where the cavity 162 of the actuator 106 arranged on the bottom surface is made sufficiently shallow, and the case where the vibration region of the actuator 106 arranged on the side wall is made sufficiently large or long. And the relationship between the amount of ink stored in the ink tank and the resonance frequency fs of the ink and the vibrating section. It can be seen that as the amount of ink in the ink tank decreases, the ink and the resonance frequency fs of the vibrating part gradually change.

More specifically, the case where the process in which the ink is gradually consumed can be detected means that the liquid and the gas having different densities are both present around the vibrating region of the actuator 106 and vibrate. This is the case. As the ink is gradually consumed, the medium involved in the vibration around the vibration region of the actuator 106 decreases in the liquid and increases in the gas.

For example, in the case where the actuator 106 is disposed horizontally with respect to the ink level, t
When smaller than ink-max, the medium involved in the vibration of the actuator 106 includes both ink and gas. Therefore, using the area S of the vibration region of the actuator 106 and expressing the state where M′max or less in Equation 4 is the additional 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, if the actuator 106 is arranged substantially horizontally with respect to the ink surface, the tair becomes larger. Increases and 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 expression of only the density of the liquid in Expression 7 is that the density of the liquid is
This is because it is assumed that the density of air is negligibly small.

When the actuator 106 is disposed substantially perpendicular to the ink liquid level, the medium related to the vibration of the actuator 106 in the vibration area of the actuator 106 and the vibration area of the actuator 106 The medium involved is considered to be an equivalent circuit (not shown) in parallel with the region where only gas is present. Assuming that the area of a region where only the medium related to the vibration of the actuator 106 is ink is Sink and the area of a region where only the medium related 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)

Expression 9 is applied when ink is not held in the cavity of the actuator 106. The additional inertance when the ink is held in the cavity of the actuator 106 can be calculated by the sum of M ′ according to Equation 9 and M′cav of Equation 7. Since the vibration of the actuator 106 changes from the depth of tink-max to the depth at which the ink remains (d), the actuator 106 is arranged on the bottom surface so that the depth of the ink remaining is slightly smaller than tink-max. If you have
It is not possible to detect a process in which the ink gradually decreases. In this case, a change in ink amount is detected from a change in vibration of the actuator in a slight change in ink amount from tink-max to the remaining depth d. In addition, if the diameter of the opening (cavity) is small, it is difficult to detect the amount of ink in the passage process because the vibration change of the actuator while passing through the opening is very small. It detects whether it is above or below the opening.

For example, the curve Y in FIG. 3A shows the relationship between the amount of ink in the ink tank and the ink and the resonance frequency fs of the vibrating portion 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 amount differences 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 binaryly detect whether a predetermined amount of ink remains in the ink tank.

In the method of detecting the presence or absence of liquid using the actuator 106, the presence or absence of ink is detected by the diaphragm 176 being in direct contact with the liquid. High accuracy. Further, the method of detecting the presence or absence of ink by conductivity using electrodes can be affected by the position of the electrodes attached to the liquid container and the type of ink.
6, the method of detecting the presence or absence of liquid is hardly affected by the mounting position of the actuator 106 on the liquid container and the type of ink.

It is preferable that the vibration frequency of the piezoelectric layer 160 is set in the non-audible range to make the sound generated during the operation of the actuator 106 quiet.

FIG. 3B shows an example of the relationship between the ink density and the resonance frequency fs of the ink and the vibrating section. Here, ink is described as an example of the liquid,
“Ink full” and “ink empty” mean two relative states, and do not mean a so-called ink full state and an ink end state. As shown in FIG. 3B, when the ink density is high, the additional inertance increases, so that the resonance frequency fs decreases. 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 that store 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, it can detect the state of the liquid even when the cavity 162 is not filled with the liquid.

The resonance frequency fs is a function of the inertance M. The inertance M is the inertance Mac of the vibrating part.
This 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 medium near the vibrating part. In other words, it refers to an increase in the mass of the vibrating part due to the apparent absorption of the medium by the vibration of the vibrating part (inertance related to the vibration increases).

Therefore, M′cav is equal to M′max in equation (4).
If greater, then all of the apparently absorbing media is liquid remaining in cavity 162. Therefore, it is the same as the state where the liquid is filled in the liquid container. In this case, since the medium related to the vibration does not become smaller than M'max, a change cannot be detected even if the ink is consumed.

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. Note that the condition M′max> M′cav at which the actuator 106 can accurately detect the state of the liquid is such that the cavity 1
Regardless of the shape of 62.

Here, M′cav is the mass inertance of a liquid having a volume substantially equal to the volume of the cavity 162. Therefore, from the inequality M'max>M'cav, the condition under which the actuator 106 can accurately detect the state of the liquid can be expressed as the condition of the capacity of the cavity 162. For example, the opening 161 of the circular cavity 162
Let a 'be a radius and d be the depth of cavity 162, then M'max> ρ × d / πa ² (Equation 10). By expanding Expression 10, the condition of a / d> 3 × π / 8 (Expression 11) is obtained. Therefore, if the actuator 106 has the cavity 162 that is the radius a of the opening 161 and the depth d of the cavity 162 that satisfy Equation 11, the liquid in the liquid container is empty and the liquid in the cavity 162 is Even if is left, the state of the liquid can be detected without malfunction.

Equations (10) and (11) indicate that the cavity 162
Holds only when the shape is circular. Cavity 162
Is not circular, the relationship between the dimensions such as the width and length of the cavity and the depth can be derived by using the corresponding expression of M'max and replacing πa ² in the expression 10 with the area.

Since the additional inertance M ′ also affects the acoustic impedance characteristics, a method for measuring the back electromotive force generated in the actuator 106 by the residual vibration is as follows.
It can be said that at least a change in acoustic impedance is detected.

According to this embodiment, the actuator 106 generates vibration, and the back electromotive force generated in the actuator 106 due to the 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,
Vibrating with a range of liquid in contact with it,
The piezoelectric layer 160 bends and deforms. This bending deformation generates a back electromotive force voltage, and the upper electrode 164 and the lower electrode 1
The counter electromotive force voltage is transmitted to 66. The state of the medium may be detected by utilizing this phenomenon. For example, in an ink jet recording apparatus, the state of the ink tank or the ink inside the ink tank is detected by utilizing the vibration around the vibrating portion of the actuator that occurs with the reciprocation of the carriage due to the scan of the print head during printing. Is also good.

FIGS. 4 (A), 4 (B) and 4 (C)
8 shows a waveform of the residual vibration of the actuator 106 after the actuator 106 is vibrated and a method of measuring the residual vibration. Actuator 106 in ink cartridge
The rise and fall of the ink level at the mounting position level can be detected by a change in the frequency or amplitude of the residual vibration after the actuator 106 oscillates. FIG.
4A to 4C, the vertical axis represents the voltage of the back electromotive force generated by the residual vibration of the actuator 106, and the horizontal axis represents time. Due to the residual vibration of the actuator 106, a waveform of a voltage analog signal is generated as shown in FIGS. 4 (A) to 4 (C). Next, the analog signal is converted into a digital numerical value corresponding to the frequency of the signal. In the example shown in FIGS. 4A to 4C,
The time during which four pulses from the fourth pulse to the eighth pulse of the analog signal are generated is measured.

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. Then, a digital signal in which the period from 4 counts to 8 counts is High is generated, and the time from 4 counts to 8 counts is measured by a predetermined clock pulse.

FIG. 4A shows a waveform when the ink level is higher than the mounting position level of the actuator 106. On the other hand, FIG. 4B shows a waveform when there is no ink at the mounting position level of the actuator 106.
Comparing FIG. 4A and FIG. 4B, it can be seen that FIG. 4A has a longer time from 4 counts to 8 counts than FIG. 4B. 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. The resonance frequency can be obtained based on this time. The clock pulse is, for example, a clock pulse equal to a clock for controlling a semiconductor memory device or the like attached to the ink cartridge. Further, 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. 4, 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. Further, when the quality of the ink is unstable and the fluctuation of the amplitude of the pulse is large, 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, a digital signal that is High for a predetermined period is generated, and the number of times that the predetermined reference voltage is crossed from the low voltage side to the high voltage side in the predetermined period is counted. The presence or absence of ink can be detected by measuring the count number.

Further, as can be seen by comparing FIGS. 4A and 4B, 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. 4A and the top of the back electromotive force waveform of FIG. 4B. After the actuator 106 oscillates, a high-level digital signal is generated for a predetermined period. When the back electromotive force waveform 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. 4C shows an example in which the time from the fourth count to the eighth count of the pulse waveform shown in FIG. 4A is measured using a predetermined clock pulse. In this figure, five clock pulses appear between the fourth and eighth counts (actually, one clock pulse appears).
A clock pulse for 200 counts to 200 counts appears, but here, for simplicity, description will be made with a small number of clock pulses.) Since the clock pulse is a pulse having a fixed period, time can be measured by counting the number of clock pulses. The resonance frequency can be obtained by measuring the time between the fourth and eighth counts. The clock pulse preferably has a period shorter than the period of the back electromotive force waveform.
If it is about kHz, it is preferable that the clock pulse has a high frequency such as 16 MHz.

FIG. 5 shows a recording apparatus control unit for detecting the change in acoustic impedance to detect the consumption state of the liquid in the liquid container 1 and controlling the ink jet recording apparatus based on the detected result. 200
0 is shown.

The recording device control unit 2000 supplies a voltage for driving the actuator 106 to the actuator 106 mounted on the liquid container 1, and detects a liquid consumption state from a change in acoustic impedance detected by the actuator 106 as a result. A liquid consumption state detection unit 1200;
A control circuit unit 1500 that controls the printing apparatus based on the detection result of the presence or absence of liquid output by the liquid consumption state detection unit 1200
And.

The control circuit 1500 controls the printing apparatus operation control unit 1402 based on the detection result of the presence or absence of liquid output from the liquid consumption state detection unit 1200.
And a recording device operation control unit 1402 that controls the operation of the recording device based on an instruction from the control unit 1400.
The control circuit unit 1500 includes a presentation processing unit 1404, a printing operation control unit 1406, an ink replenishment processing unit 1408, a cartridge replacement processing unit 1410, and a print data storage processing unit 14 whose operations are controlled by the printing apparatus operation control unit 1402.
12 and a print data storage unit 1414.

The printing apparatus control unit 2000 may be provided inside the ink jet printing apparatus, but some functions of the printing apparatus control unit 2000 may be provided outside. For example, the function of the control circuit 1500 may be provided to an external device such as a computer connected to the recording device. Further, some functions of the recording device control unit 2000 may be stored and supplied as a program on a recording medium. By supplying a part of the functions of the recording device control unit 2000 to a computer connected to the recording device as a program stored in a recording medium, if some of the functions of the recording device control unit 2000 are improved at a later date, In addition, a program for executing the latest function can be stored in a storage medium of a computer, and the operation of the recording apparatus can be controlled using the latest function at all times.

Further, some functions of the recording device control unit 2000 may be transmitted as a program from an information processing device such as a server to a terminal such as a computer connected to the recording device via an electric communication line. . In this case, the latest function can be easily obtained from the server via the telecommunication line and stored in the storage device of the computer, so that the recording device can always execute the latest function.

The liquid consumption state detecting section 1200 drives the actuator 106 to detect the presence or absence of liquid in the liquid container 1 from the change in acoustic impedance. For example, the liquid consumption state detection unit 1200 includes a measurement circuit unit 800 that measures a back electromotive force, for example, a voltage value, generated by the actuator 106 due to the residual vibration, and an inside of the liquid container 1 based on the back electromotive force measured by the measurement circuit unit 800. And a detection circuit section 1100 that outputs a signal indicating the presence or absence of the liquid.

The measurement circuit section 800 includes the actuator 10
Drive voltage generation unit 850 that generates a drive voltage for driving the drive voltage generator 6
Having. The driving voltage generated by the driving voltage generation unit 850 drives the actuator 106 mounted on the liquid container 1 to oscillate. The actuator 106 continues to vibrate after the drive oscillation. Due to the residual vibration, the actuator 106 itself generates a back electromotive force. The measurement circuit section 800 converts an analog signal having a back electromotive force waveform generated by the actuator 106 into a digital signal having the same frequency and outputs the digital signal to the digital circuit section 900.

The detection circuit section 1100 includes a measurement circuit section 800
Has a digital circuit unit 900 for measuring the time spent for the oscillation of the predetermined number of pulses of the digital signal output by the digital circuit unit, and a liquid presence / absence determination unit 1000 for determining the presence / absence of the liquid based on the time counted by the digital circuit unit 900. .

In this embodiment, the digital circuit section 90
As shown in FIGS. 4A and 4B, 0 indicates that the fourth to eighth counts in the back electromotive force waveform output from the measurement circuit unit 800 output a High signal. Further, as shown in FIG.
Counts the number of pulses of a predetermined clock pulse (having a period shorter than the period of the back electromotive force waveform) during the High period from the fourth count to the eighth count in the digital signal. By counting the number of clock pulses having a fixed period, the time from the fourth count to the eighth count can be measured.
For example, in FIG. 4C, five clock pulses exist, and the time can be calculated by multiplying the five counts by the cycle of the clock pulse.

Although a low-frequency clock pulse is described here for simplicity, a high-frequency clock pulse such as 16 MHz is actually used. The liquid presence / absence determination unit 1000 includes the digital circuit unit 9
Based on the count value output by 00, the presence or absence of liquid in the liquid container 1 is determined, and the determination result is output to the control circuit unit 1500.

When the liquid consumption state detection unit 1200 outputs the determination result that there is no liquid, the control unit 1400 controls the printing apparatus operation control unit 1402 to perform a predetermined low ink amount handling process. The low ink amount handling process is a process of prohibiting or suppressing an operation of the recording apparatus such as improper printing in consideration of a low ink level. The printing device operation control unit 1402, based on an instruction from the control unit 1400, provides a presentation processing unit 1404, a printing operation control unit 1406, an ink replenishment processing unit 1408, a cartridge replacement processing unit 1410,
Alternatively, the operation of the print data storage processing unit 1412 is controlled to execute the low ink amount handling process.

The presentation processing unit 1404 includes the actuator 1
Information corresponding to the presence or absence of the liquid in the liquid container 1 detected by 06 is presented. Display 1 for information presentation
416 and an alert by the speaker 1418. The display 1416 is, for example, a display panel of a recording device or a screen of a computer connected to the recording device. Alternatively, the presentation processing unit 1404 controls the speaker 141
8, when the actuator 106 detects that there is no liquid, a notification sound is output from the speaker 1418.
The speaker 1418 may be a speaker of a recording device or a speaker of an external device such as a computer connected to the recording device. It is also preferable to use a voice signal as the notification sound, and a synthesized voice indicating the ink consumption state may be generated by the voice synthesis processing.

[0147] The printing operation control unit 1406 includes the printing operation unit 1
420 is controlled to stop the printing operation of the recording device.
By stopping the printing operation, the printing operation after the ink is exhausted is avoided. Also, as another example of the low ink amount handling process, the printing operation control unit 1406 may prohibit the end of a certain printing process before moving to the next printing process. By prohibiting such printing processing, it is possible to avoid printing from being stopped during printing of a single printing process, for example, a series of sentences. Also, as an example of prohibition of print processing, in order to prevent print processing from being stopped during printing of one page,
It is also preferable to prohibit printing processing after the end of a page break.

The ink replenishment processing unit 1408 controls the ink replenishing device 1422 to automatically replenish the ink cartridge with ink. Printing can be continued by replenishing the ink.

The cartridge exchange processing section 1410 controls the cartridge exchange device 1424 to automatically exchange the ink cartridge. By such a response process,
The printing operation can be continued without bothering the user.

The print data storage processing section 1412 stores print data before printing is completed in the print data storage section 1414 as a process for handling a low ink amount. This print data is print data sent to the recording device after detecting the ink end. By storing the print data, the loss of the print data before printing can be avoided.

As for the components 1404 to 1412,
Not all of them need to be provided in the recording device control unit 2000. Further, it is not necessary to perform the low ink amount handling process in all the components 1404 to 1412, and it is sufficient that at least one low ink amount handling process is performed.
For example, if the ink replenishment processing unit 1408 or the cartridge replacement processing unit 1410 performs the processing, the print operation control unit 1406 does not need to perform the print operation stop processing.

In addition, a configuration for performing a process for a low ink amount, that is, a configuration for avoiding an inappropriate operation due to a shortage of ink, other than the above-described example, may be provided. Further, it is preferable that the above-described low-ink-amount processing is executed after printing is performed for a “predetermined margin” after the actuator 106 detects “no liquid” at the mounting position. The “predetermined margin” is set to an appropriate value that is smaller than the print amount until all the ink is consumed after the detection of “no liquid” by the actuator 106.

FIG. 6 shows a recording apparatus control unit 2 according to another embodiment.
FIG. 2 is a block diagram showing 002. In the present embodiment, three actuators 106A, 106B, and 106C are mounted on the liquid container 1. Three actuators 1
06A, 106B, and 106C are installed at different positions along the liquid level lowering direction due to liquid consumption.

The measuring circuit section 802 shown in FIG. 6 includes three actuators 106A and 106 mounted on the liquid container 1.
Drive voltage generators 850A and 850 for applying voltages for driving the actuators to B and 106C, respectively.
B, and 850C. The digital circuit unit 902 in the detection circuit unit 1102 includes the actuators 106A and 106A.
The back EMF signals generated by 6B and 106C are received via the measurement circuit unit 802, and the number of pulses of each back EMF signal within a predetermined time is counted. Further, the liquid presence / absence determination unit 1002, based on the count value of each back electromotive force signal output by the digital circuit unit 902,
The presence or absence of liquid in the liquid container 1 is determined.

In the present embodiment, since the plurality of actuators 106A to 106C are mounted at different positions in the liquid level lowering direction, it is possible to detect the liquid consumption state at the mounting position of each actuator stepwise. it can. The configuration of the printing apparatus control unit 2002 other than the liquid consumption state detection unit 1202 is the same as that of the printing apparatus control unit 2 shown in FIG.
Since the configuration is the same as 000, the description is omitted.

The output signal of each actuator differs depending on whether the liquid level is higher than the mounting position level of each actuator. For example, if the frequency or amplitude of the detected back electromotive force changes significantly, the detection signal changes accordingly. Based on each detection signal, the liquid consumption state detection unit 1202 determines whether the liquid level of the liquid is equal to each of the actuators 106A and 106A.
It is possible to determine whether or not the vehicle has passed the mounting position levels of B and 106C. The detection process is periodically performed, for example, at a predetermined timing.

Here, a state in which the liquid level is lower than the mounting position of the actuator is referred to as a “liquid-free state”, and a state in which the liquid level is higher than the actuator is referred to as a “liquid-present state”. When the liquid level passes through the actuator, the detection result changes from “the state with liquid” to “the state without liquid”. In the present embodiment, detection of passage of the liquid surface indicates such a change in the detection result.

As a feature of this embodiment, the control unit 1400
Is the actuator used to detect the impedance,
Switching is performed along the direction in which the liquid level of the liquid decreases as the liquid consumption progresses. More specifically, immediately after the mounting of the liquid container 1, that is, in the liquid full state, only the actuator 106A is used. The liquid is consumed and the liquid level is
After passing through A, the actuator 106A detects a liquid-out state. In response, control unit 1400 switches the liquid detection position to the middle stage, that is, the consumption of liquid is detected using only actuator 106B. Similarly, when the actuator 106B detects the absence of liquid, the detection position is switched to the lowermost actuator 106C.

According to the present embodiment, since the detection position is sequentially switched downward, it is not necessary for all the actuators to always operate. That is, the frequency of operation of the actuator is low. Therefore, the amount of data processing in the control unit 1400 can be suppressed. As a result, the detection operation does not lower the throughput of the printing operation.

In the present embodiment, the number of actuators is three. However, the number of actuators may be any number as long as it is three or more. Further, the intervals between the actuators may not be constant. For example, it is preferable that the lower the liquid level, the narrower the interval between the actuators. Such a modification can be similarly applied to other embodiments described below.

FIG. 7 shows the recording apparatus control unit 20 shown in FIG.
An embodiment in which 00 is modified is shown. The liquid container 1 in FIG.
It is mounted on a carriage so as to communicate with a head unit 1300 for discharging and printing the liquid in the liquid container 1 onto a recording medium such as recording paper. The head unit 1300 is driven by a head driving unit 1440. Further, the recording apparatus in FIG. 7 includes a cleaning unit 1436 that suctions liquid from the head unit 1300 and cleans nozzles of the head unit 1300. When the cleaning drive unit 1432 drives the pump 1434, the cleaning unit 1436 sucks the liquid from the head unit 1300.

The control circuit 1502 of the printing apparatus control unit 2004 shown in FIG. 7 is different from the printing apparatus control unit 200 shown in FIG.
In addition to the elements of 0, a liquid ejection counter (dot counter) 1450 that counts the number of ink droplets ejected by the head unit 1300 and an ink consumption amount is calculated based on the number of ink droplets counted by the liquid ejection counter 1450. The cleaning driving unit 1 based on the ink consumption state detected by the liquid consumption amount calculation unit 1452 and the liquid consumption state detection unit 1210
A cleaning controller 1442 for controlling the 432. In addition, the detection circuit unit 1104 includes a liquid consumption state correction unit 1010 that corrects the number of ink droplets ejected from the head unit 1300 counted by the liquid ejection counter 1450 based on the ink consumption state detected using the actuator 106. .

Next, the operation of the newly added element in FIG. 7 will be described. Liquid discharge counter 1450
Counts the number of ink droplets ejected from the head unit 1300 during printing, and outputs the counted number to the liquid consumption calculating unit 1452. The liquid consumption calculation unit 1452 performs the operation of the liquid ejection counter 1
Based on the count value of 450, the amount of ink ejected from the head unit is calculated.

Further, by applying a drive signal which is not related to printing to the print head to cause the ink droplets to be ejected idly,
Ink is also consumed by recovering an irregular meniscus near the nozzle opening of the head unit 1300 or by preventing ink clogging at the nozzle opening (flushing operation). Therefore, the liquid discharge counter 14
Reference numeral 50 also counts the number of ink droplets ejected by the flushing operation, and outputs the counted number to the liquid consumption calculator 1452.

The liquid consumption calculating section 1452 calculates the ink consumption from the number of ink ejections from the head section 1300 in the printing operation and the flushing operation, and sends the calculated ink consumption to the liquid consumption state correcting section 1010. Output. The ink amount calculated by the liquid consumption calculating unit 1452 is displayed on the display 1416 of the presentation processing unit 1404.

Further, when the head 1300 is cleaned by the cleaning unit 1436 (cleaning operation), the ink in the liquid container 1 is consumed by sucking the ink in the head 1300. Accordingly, the liquid consumption calculating unit 1452 determines the time during which the cleaning drive unit 1432 drives the pump 1434 via the cleaning control unit 1442 (for example, the time during which the pump 1434 is energized).
By multiplying this by the amount of ink absorbed by the pump 1434 per hour, the amount of ink consumed by cleaning is calculated.

Therefore, the liquid consumption calculating section 1452
Are the liquid discharge counter 1450 and the cleaning controller 1
442, the consumed ink amount is calculated. The liquid consumption state correction unit 1010 includes a liquid consumption amount calculation unit 145.
The calculated value of 2 is corrected based on the determination result of the liquid presence / absence determination unit 1000.

The reason why the two outputs of the liquid presence / absence determining unit 1000 and the liquid consumption calculating unit 1452 are used for detecting the ink consumption state will be described below.

The output of the liquid presence / absence determination unit 1000 is information obtained by actually measuring the liquid level of the liquid by the actuator 106. On the other hand, the output of the liquid consumption calculator 1452 is:
This is an estimated ink consumption calculated from the number of ink droplets counted by the liquid ejection counter 1450 and the drive time of the pump.

The calculated value depends on the printing mode and usage environment set by the user, for example, when the room temperature is extremely high or low, or when the elapsed time after opening the ink cartridge is long, In some cases, errors may occur due to changes in the viscosity of the ink or ink.

Therefore, the liquid consumption state correction unit 1010
The ink consumption calculated by the liquid consumption calculation unit 1452 is corrected based on the determination result of the presence or absence of the ink output from the liquid presence / absence determination unit 1000. Further, the liquid consumption state correction unit 1010 corrects the parameters of the calculation formula used by the liquid consumption calculation unit 1452 to calculate the ink consumption based on the determination result of the presence or absence of the ink output from the liquid presence determination unit 1000. I do. By correcting the parameters of the calculation formula in this way, the calculation formula can be adapted to the environment in which the ink cartridge is used. As a result, the value obtained by the calculation formula becomes closer to the actually used value.

When the actuator 106 detects “out of ink” at the mounting position, the printing apparatus operation control unit 1
402, a printing operation control unit 1406, an ink replenishment processing unit 1408, a cartridge replacement processing unit 1410,
The print data storage processing unit 1412 and the cleaning control unit 1442 perform a predetermined low ink amount processing.

The printing operation control unit 1406 controls the head driving unit 1440 to stop the discharge of the ink in the head unit 1300 or to reduce the discharge amount of the ink. This avoids a printing operation after the ink runs out.

The cleaning control unit 1442 performs the low ink handling process by prohibiting the cleaning operation of the head unit 1300 by the cleaning unit 1436, reducing the number of cleaning operations, and weakening the suction force of the pump 1434. Reduce the amount of suction. Head part 1
During cleaning of 300, a relatively large amount of ink is sucked from the head unit 1300. Therefore, by prohibiting the cleaning operation when the ink becomes low, it is possible to prevent the remaining ink from being sucked from the head unit 1300 for cleaning, and to avoid a situation in which the amount of ink is insufficient for cleaning. Alternatively, as described above, the number of times of cleaning may be reduced, or the suction force of the pump 1434 may be reduced. Control unit 1
400 selects what kind of low ink processing the printing operation control unit 1406 and the cleaning control unit 1442 execute based on the remaining amount of ink in the liquid container 1.

FIG. 8 shows the recording apparatus control unit 20 shown in FIG.
14 shows an embodiment obtained by modifying No. 04. In this embodiment, the semiconductor storage means 7 is mounted on the liquid container 1, and the recording device control unit 2006 has an information storage control circuit unit 1444.
The other configuration is the same as that of the recording device control unit 2004 shown in FIG. Therefore, the description of the elements that are not related to the semiconductor storage means 7 and the information storage control means 1444 will be omitted.

The liquid container 1 of the present embodiment has the actuator 106 and the semiconductor memory 7. The semiconductor storage means 7 is, for example, a rewritable memory such as an EEPROM. The control circuit unit 1506 includes an information storage control circuit unit 1444.

The liquid consumption state detecting section 1210 controls the actuator 106 to detect the consumption state of the liquid in the liquid container 1, and outputs the consumption related information relating to the detection of the liquid consumption state using the actuator 106 to the control circuit section. Output to 1506.

The control section 1400 includes the information storage control circuit section 1
Via 444, consumption-related information is written into the semiconductor storage means 7. Further, the information storage control circuit unit 1444 reads the consumption related information from the semiconductor storage unit 7 and
Output to 00.

Next, the semiconductor memory means 7 will be described in detail. The semiconductor storage unit 7 stores consumption-related information related to detection of a liquid consumption state using the actuator 106. The consumption-related information includes information on the detected consumption state of the liquid. The information storage control circuit 1444 writes the consumption state information obtained by using the actuator 106 to the semiconductor storage unit 7. Then, the consumption state information is read out and used in the recording device control unit 2006.

Storing the consumption state information in the semiconductor storage means 7 is particularly advantageous when the liquid container 1 is detached. For example, it is assumed that the liquid container 1 is detached from the ink jet recording apparatus while the liquid is partially consumed. At this time, the semiconductor storage means 7 storing the liquid consumption state is always present together with the liquid container 1. The liquid container 1 is mounted on the same ink jet recording apparatus again or mounted on another ink jet recording apparatus. At this time, the liquid consumption state is read from the semiconductor storage means 7, and the recording device control unit 2006 operates based on the liquid consumption state. For example, even when the liquid container 1 in which the liquid is empty or the liquid remaining amount is small is mounted, the fact is notified to the user. As described above, even when the liquid container 1 is detached, the previous consumption state information of the liquid container 1 can be reliably used.

The semiconductor storage means 7 may further store the liquid consumption state calculated by the liquid consumption calculating section 1452 based on the number of ink droplets counted by the liquid discharge counter 1450. The actuator 106 can surely detect the passage of the ink level at the mounting position of the actuator 106, but it is difficult to detect the ink consumption state before and after the passage of the ink level. Therefore, it is preferable to estimate the ink consumption states before and after the passage of the liquid level from the liquid consumption state calculated by the liquid consumption amount calculation unit 1452, and store the estimated value in the semiconductor storage unit 7.

The consumption-related information includes detection characteristic information to be detected according to the liquid consumption state. In the present embodiment, pre-consumption detection characteristic information and post-consumption detection characteristic information are stored as the detection characteristic information. The pre-consumption detection characteristic information indicates detection characteristics before ink consumption is started, that is, detection characteristics in an ink full state. The post-consumption detection characteristic information is a detection characteristic to be detected when the ink is consumed up to a predetermined detection target, specifically, a detection characteristic when the ink liquid level falls below the mounting position level of the actuator 106. Show.

The information storage control circuit section 1444 reads the detection characteristic information from the semiconductor storage means 7, and the liquid consumption state detection section 1210 detects the liquid consumption state using the actuator 106 based on the detection characteristic information. When the detection signal corresponding to the pre-consumption detection characteristic is obtained, it is considered that the consumption of the ink has not yet progressed and the remaining amount of the ink is large. At least, the ink level is
It is certain to be higher. On the other hand, when a detection signal corresponding to the post-consumption detection characteristic is obtained, the consumption of ink proceeds and the remaining amount is small, so that it can be seen that the ink liquid level is lower than the actuator 106.

One of the advantages of storing the detection characteristic information in the semiconductor storage means 7 will be described.

The detection characteristic information is determined by various factors such as the shape of the liquid container 1, the specifications of the actuator 106, the specifications of the ink, and the like. Therefore, when a design change such as improvement is made, the detection characteristics may also change. If the liquid consumption state detection unit 1210 always uses the same detection characteristic information, it is difficult to cope with such a change in the detection characteristic. On the other hand, in the present embodiment, the detection characteristic information is stored in the semiconductor storage means 7 and used. Therefore, it is possible to easily cope with a change in the detection characteristics. For example, a new specification of a liquid container 1
Is provided, the recording device control unit 2006 can easily use the detection characteristic information of the liquid container 1.

Even when the specifications of the liquid container 1 are the same, the detection characteristics may be different due to manufacturing variations. For example, the detection characteristics may be different depending on the shape and thickness of the liquid container 1. Therefore, more preferably, the detection characteristic information for each individual liquid container 1 is measured and stored in the semiconductor storage means 7. In this embodiment, since each liquid container 1 has the semiconductor storage means 7, the semiconductor storage means 7 can store unique detection characteristic information. As a result, the influence of the manufacturing variation on the detection can be reduced, and the detection accuracy can be improved. As described above, the present embodiment is advantageous because it can cope with the difference in the detection characteristics of the individual liquid containers 1.

FIG. 9 shows the recording apparatus control unit 20 shown in FIG.
It is a flowchart which shows the operation procedure of 06.

First, it is determined whether or not the ink cartridge has been mounted (S10). That is, it is detected that a new ink cartridge or a partially used ink cartridge has been installed. For this processing, a switch or the like (not shown) provided in the inkjet recording apparatus is used.

When the ink cartridge is mounted, consumption-related information including detection characteristic information and the like is read from the semiconductor storage means 7 (S12). The presentation processing unit 1404, the printing operation control unit 1406, the ink replenishment processing unit 1408, the cartridge replacement processing unit 1410 of the recording device control unit 2008,
The print data storage processing unit 1412 and the cleaning control unit 1442 use the read consumption-related information. For example, if the read consumption-related information indicates that the remaining amount of liquid in the liquid container 1 is small, the display 141
6 indicates that the remaining amount of liquid is low,
00 operation is stopped.

The liquid consumption state detector 1210 detects the liquid consumption state using the actuator 106 based on the read detection characteristic information (S14). Based on the detected liquid consumption state, the presence or absence of liquid in the liquid container 1 is determined (S16). When "no liquid" is detected, a liquid-out-of-liquid handling step (S18) is executed. As the liquid-free process (S18), the print data storage processing unit 1412 stores the print data (S24), the print operation control unit 1406 stops the print operation (S26), and the presentation processing unit 1404.
(S28) of displaying no liquid.

In this case, the liquid absence display step (S2
According to the instruction of 8), the ink is refilled in the ink jet recording apparatus by the user replacing the ink cartridge as described later.

Alternatively, the ink cartridge may be automatically replaced (S20) by the cartridge replacement processing unit 1410 as a liquid-out-of-liquid handling step (S18),
The ink may be automatically replenished by the ink replenishment processing unit 1408 (S22). In this case, the ink is automatically replenished to the ink jet recording apparatus, and there is no need for the user to replace the ink cartridge. In this case, the process returns to the liquid consumption information reading step (S12) without going through the cartridge replacement determination step (S32) described later. When the ink replenishment step (S22) is performed, after the ink is replenished, information on how much ink has been replenished in the recording apparatus is stored in the semiconductor storage means 7 (S22).
34).

After the print data storing step (S24), the printing operation stopping step (S26), and the liquid absence display step (S28) are executed as the liquid absence handling means (S18), the detected liquid consumption state is stored in the semiconductor memory. Means 7
(S30). Since the fact that there is no ink in the ink cartridge is transmitted to the user in the liquid absence display step (S28), the user replaces the ink cartridge in accordance with the instruction of the liquid absence display step (S28). In this case (S32, Y), the process returns to the liquid consumption state detection step (S14). On the other hand, if the user does not replace the ink cartridge, a display prompting the user to replace the ink cartridge is presented on the display or the speaker, and the process ends.

FIG. 10 is a diagram showing a circuit configuration of the measurement circuit section 800. The measurement circuit section 800 includes the drive voltage generation section 8
50, reference potential generator 816, high-pass filter 82
4, an amplification unit 860 and a comparator 836. The drive voltage generation unit 850 includes two bipolar transistors, an NPN transistor 810 and a PNP transistor 812, whose bases B and emitters E are connected in parallel complementarily. NPN transistor 810 and PNP
The type transistor 812 is a transistor for driving the actuator 106. Actuator 106
Has one terminal connected to the emitter E of the NPN transistor 810 and the PNP transistor 812 connected to each other, and the other terminal connected to the ground GND. The other terminal of the actuator 106 is connected to a power supply Vc
c (5 V).

When the trigger signal input from the terminal 840 to the drive voltage generator 850 changes from low to high,
NPN transistor 810 and PN connected to each other
The base B of the P-type transistor 812 rises and NP
N-type transistor 810 and PNP-type transistor 81
2 amplifies the current of the input trigger signal and gives it to the actuator 106. In the case of FIG. 10, a voltage between the emitter E and the collector C of the PNP transistor 812 is supplied to the actuator 106. Therefore, the actuator 106 is rapidly charged and oscillates. Further, the actuator 106 generates a back electromotive force due to the vibration remaining after the oscillation. The back electromotive force generated by the residual vibration of the actuator 106 is
4 to the amplifier 860.

The NPN transistor 810 (also the PNP transistor 812) has a PN junction between the base B and the emitter E. When the potential difference between the base B and the emitter E is 0.6 V or less, almost no current flows to the emitter E side. When the voltage exceeds 0.6 V, a greatly amplified current flows to the emitter E. That is, the NPN transistor 8
10 and the PNP transistor 812 are each 0.1.
It has a dead zone or bias voltage of 6V, and the NPN transistor 810 and the PNP transistor 812 have a bias voltage of about 1.2V in total. If the terminal potential including the back electromotive force of the actuator 106 is within the range of the dead zone, the transistor does not operate and no current flows into the emitter E, and the residual vibration of the actuator 106 is suppressed due to the operation of the transistor. Nothing. If there is no dead zone, the voltage of the actuator 106 is controlled by the transistor to be a constant value, and the back electromotive force cannot be checked.

In FIG. 10, an NPN transistor 810 and a PNP transistor 812 are used as bipolar transistors, but a field effect transistor may be used instead of a bipolar transistor.
When a field effect transistor is used, an N type field effect transistor is arranged at a position where the NPN type transistor in FIG. 10 is arranged. The gate of the N-type field effect transistor is arranged at the position of the base B of the NPN transistor 810, and the source is arranged at the position of the emitter E. Also, P
A P-type field-effect transistor is provided at a position where the NP-type transistor 812 is provided. The gate of the P-type field effect transistor is arranged at the position of the base B of the PNP transistor 812, and the source is arranged at the position of the emitter E. Further, the gates and the sources of the P-type field effect transistor and the N-type field effect transistor are connected.
The actuator 106 preferably has one terminal connected to the sources of the P-type and N-type field-effect transistors connected to each other, and the other terminal connected to the power supply Vcc or the ground GND.

The high-pass filter 824 includes the capacitor 8
26 and a resistor 828. Drive voltage generator 8
The output of 50 is output to the amplifier 860 via such a high-pass filter 824. High-pass filter 82
Reference numeral 4 outputs high-frequency components of the output of the actuator 106 to the amplifying unit 860, while removing low-frequency components.
Further, the high-pass filter 824 has a role of adjusting the output of the amplifying unit 860 so as to fall within a range of 0 to 5 V around a reference potential B (described later).

The reference potential generator 816 has resistors 817, 818, and 820 connected in series, and a capacitor 822 connected in parallel with the resistor 820. In this case, the resistance 817 and the resistance 820 are both about 5 kΩ,
18 is about 500Ω. Thereby, the reference potential generation unit 816 generates two stable DC potentials of about 2 to 3 V as the reference potentials A and B, and outputs the high-pass filter 824.
And an amplifier 860 and a comparator 836, respectively. Therefore, the high-pass filter 824 and the amplifying unit 86
The voltage of the signal waveform output from the resistor 818 and the resistor 8
It oscillates around a reference potential B generated between 20.

The amplifying section 860 has an operational amplifier 834 and resistors 830 and 832. The operational amplifier 834 and the resistors 830 and 832 are configured as a non-inverting amplifier circuit that amplifies and outputs an input signal without inverting it. The back electromotive force signal output from the drive voltage generation unit 850 is input to the + terminal of the operational amplifier 834 via the high-pass filter 824. The negative terminal of the operational amplifier 834 is connected to the negative feedback resistor 830.
Through the resistor 832 and to the reference potential B. As a result, the weak back electromotive force signal output from the actuator 106 is amplified around the reference potential B and output to the comparator 836. The waveform of the back electromotive force signal thus amplified can be represented as the analog waveform shown in FIG.

The voltage of the back electromotive force signal output from the amplifier 860 and the reference potential A (generated between the resistors 817 and 818) generated by the reference potential generator 816 are input to the comparator 836. When the voltage of the back electromotive force signal is higher than the reference potential A, a High signal is output, and when the voltage of the back electromotive force signal is lower than the reference potential A, a Low signal is output. As a result, a back electromotive force signal having a digital waveform is generated.
That is, while the output of the operational amplifier 834 oscillates around the reference potential B, the voltage at the negative terminal of the comparator 836 is equal to the reference potential A. Therefore, the comparator 836 sets the voltage of the back electromotive force signal based on the reference potential A. And outputs a digital signal back electromotive force signal. The comparator 836 outputs the generated digital waveform back electromotive force signal to the terminal 844.

The relationship between the reference voltage A and the reference voltage B may be reversed.

In the measurement circuit section 800 shown in FIG. 10, when no back electromotive force exists, the output of the operational amplifier 834 becomes the reference potential B, so that the output signal of the comparator 836 is always Lo.
w and should not change. By utilizing this fact, it is possible to determine whether or not the measurement circuit unit 800 is affected by noise.

For example, as shown in FIG. 10, the measuring circuit section 800 may have a noise influence judging section 880. The noise influence determination unit 880 determines the influence of noise on the back electromotive force signal, for example, according to the flow shown in FIG.

In this case, the noise influence determination unit 880 measures a normal resonance frequency (frequency of the back electromotive force signal) before the drive voltage signal is applied to the piezoelectric element (details will be described later).
The output from the comparator 836 is observed for a time equal to or longer than the required time (defined as a specified time) (S
TEP1).

The comparator 836 is provided during the specified time.
It is determined whether or not the output has changed (STEP 2).

If there is no change in the output, it is determined that the influence of noise is small, and a drive voltage signal is given to the piezoelectric element, and resonance is detected by the detection circuit unit 1100 (described in detail later with reference to FIGS. 12 and 13). Frequency measurement is performed (ST
EP3).

On the other hand, if there is a change in the output, it is determined that the influence of noise is large, and the detection circuit 11
00 is output to a display screen or the like (not shown) indicating that the measurement of the resonance frequency cannot be accurately performed.
TEP4).

As described above, according to the flowchart shown in FIG. 11, measurement of an erroneous resonance frequency due to the influence of noise can be avoided.

[0210] As described above, the supply of the drive voltage signal to the piezoelectric element is performed by the input of the trigger signal from the terminal 840. This trigger signal is input to the control device 8
40c. The control device 840c can be provided in various liquid consuming devices such as an inkjet recording device in which a liquid container is mounted, for example.

[0211] Further, instead of configuring the noise influence determination section 880 as a separate circuit, the noise influence determination section may be configured using the digital circuit section 900.

FIG. 12 shows a circuit configuration of the detection circuit section 1100 of FIG. The detection circuit unit 1100 includes a digital circuit unit 900 and a liquid presence / absence determination unit 1000. The digital circuit unit 900 includes flip-flops 910 and 918
, Counters 912 and 920, and NAND gate 91
4 and 916. When the counter 920 has counted up to the highest value (1111, 1111), it does not become (0000, 0000) even if the next clock pulse is input.
The highest value shall be maintained.

When the trigger signal is input from the terminal 842 to the clock input pin CLK of the flip-flop 910, the flip-flop 910 supplies the counter 912 with the number of pulses of the back electromotive force signal output from the measurement circuit 800. Is output to control the counter 912 to start the measurement of. Further, when the counter 912 counts eight pulses of the back electromotive force signal, the flip-flop 910 is cleared via the NAND gate 916. Therefore, the flip-flop 910 supplies a signal that has been High during the period until the back pulse voltage reaches the eighth pulse from the input of the trigger signal to the count enable terminal ENP of the counter 912.

The counter 912 counts clocks only when the signal input to the counter enable terminal ENP is High. The counter 912 starts counting the number of pulses of the back electromotive force signal after the trigger signal is input to the flip-flop 910, and when the number of pulses reaches 8, the signal input to the count enable terminal ENP is Low.
, The counting of the number of pulses is terminated. Counter 9
Reference numeral 12 denotes a signal in which the fourth pulse to the eighth pulse are High, which is output from the output pin QC to the flip-flop 9.
18 to the input pin D.

The flip-flop 918 has a counter 91
The 4th to 8th pulses output by 2 are High
Is received from the input pin D, and the terminal 846 is received.
Receives a clock having a frequency of 16 MHz from the clock input pin CLK, and outputs a signal input from the input pin D in synchronization with the clock.

[0216]

(Equation 1)

In the circuit of FIG. 12, the number of 16 MHz clock pulses existing between the fourth pulse and the eighth pulse of the back electromotive force waveform is counted.
By adding and combining a counting circuit using twelve outputs, not only the time up to the eighth count but also any count can be counted. That is, it is possible to detect times within different count intervals.

FIG. 13 shows a detailed circuit configuration of the liquid presence / absence determining section 1000 shown in FIG. Liquid presence / absence determination unit 10
00 determines the presence or absence of liquid in the liquid container 1 based on the count value of the number of 16 MHz clock pulses appearing between the fourth and eighth pulses of the back electromotive force signal output by the counter 920. The liquid presence / absence determination unit 1000
As shown in FIG. 13, an upper limit value register 1011, a lower limit value register 1012, comparison units 1014 and 1016
And an AND gate 1018. The upper limit register 1011 stores the upper limit value of the count value, and the lower limit register 1012 stores the lower limit value of the count value.

The comparing section 1014 is provided with a digital circuit section 900.
Is received from terminal B, and the upper limit of the count value is received from upper limit register 1011 via terminal A. When the count value is smaller than the upper limit value, the comparing unit 1014 outputs a High signal to the AND gate 1018. On the other hand, when the count value is equal to or more than the upper limit value, the comparing unit 1014 outputs a Low signal to the AND gate 1018. If the count value is equal to or higher than the upper limit, the frequency of the back electromotive force waveform is lower than the lower limit and the back electromotive force waveform is not measured normally, so the liquid container is not attached to the recording device or is securely attached. It may not have been.

On the other hand, comparing section 1016 receives the count value output from digital circuit section 900 from terminal A, and receives the lower limit value of the count value from lower limit register 1012 via terminal B. If the count value is greater than the lower limit,
The comparing unit 1016 outputs the High signal to the AND gate 101.
8 and a terminal 1022. On the other hand, when the count value is equal to or smaller than the lower limit, the comparing unit 1016 outputs a Low signal to the AND gate 1018 and the terminal 1022. When the count value is equal to or less than the lower limit, it means that the liquid in the liquid container 1 does not exist at the mounting position of the actuator 106.

Both comparison units 1014 and 1016 are Hi.
gh, that is, when the count value is smaller than the upper limit and larger than the lower limit,
Reference numeral 018 outputs a High signal. In this case, since the frequency of the back electromotive force waveform is lower than the upper limit, the liquid in the liquid container 1 exists at the mounting position level of the actuator 106. In addition, since the frequency of the back electromotive force waveform is higher than the lower limit, it can be seen that the liquid container 1 is securely mounted on the recording apparatus, and that the liquid exists at the mounting position level of the actuator 106. That is, when the terminal 1020 is High, the liquid container 1 is securely mounted on the recording apparatus, and a normal state exists in which the liquid exists at the mounting position level of the actuator 106.

The comparing section 1014 outputs a Low signal,
When the comparing unit 1016 outputs a High signal, that is, when the count value is equal to or more than the upper limit and larger than the lower limit, the AND gate 1018 outputs a Low signal.
A high signal is input to the terminal 1022. In this case, since the terminal 1020 is Low, it is abnormal, and since the terminal 1022 is High, it can be determined that the liquid container 1 is not mounted on the recording apparatus or is not securely mounted.

When comparing section 1014 outputs a High signal and comparing section 1016 outputs a Low signal, that is, when the count value is smaller than the upper limit and equal to or smaller than the lower limit, AND gate 1018 outputs a Low signal. I do.
In this case, since the terminal 1020 is Low, it is abnormal, and since the terminal 1022 is Low, the liquid is
It can be seen that there is not at the mounting position level.

FIG. 14 shows a method of manufacturing the actuator 106. In FIG. 14, a plurality of actuators 106
(Four in the example of FIG. 14) are integrally formed. FIG.
The actuator 106 shown in FIG. 15 is manufactured by cutting the integrally molded product of the plurality of actuators shown in FIG. A plurality of integrally formed actuators 106 shown in FIG.
When each of the piezoelectric elements is circular, the actuator 106 shown in FIG. 1 can be manufactured by cutting the integrally molded product at each actuator 106. 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 vibration plate 176, a substrate 178, an elastic wave generating means or a piezoelectric element 17
4, a terminal forming member or upper electrode terminal 168 and a terminal forming member or lower electrode terminal 170;

The piezoelectric element 174 includes a piezoelectric vibrating plate or layer 160, an upper electrode 164, and a lower electrode 166. A vibration plate 176 is formed on the upper surface of the substrate 178.
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 between the main part of the upper electrode 164 and the main part of the lower electrode 166 from above and below.

In the case shown in FIG. 14, a plurality of (four in the example of FIG. 14) piezoelectric elements 174 are formed on the vibration plate 176. A lower electrode 166 is formed on the surface of the vibration plate 176, and a piezoelectric layer 160 is formed on the surface of the lower electrode 166.
An 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. And
The four actuators 106 are separately cut and used individually.

FIG. 15 shows a cross section of a part of an actuator 106 having a rectangular piezoelectric element. FIG. 16 shows an overall cross section of the actuator 106 shown in FIG.

As shown in FIG. 16, a through hole 178a is formed in the surface of the substrate 178 facing the piezoelectric element 174. The through hole 178a is sealed by the diaphragm 176. The vibration plate 176 is formed of a material having electrical insulation and elastically deformable, such as alumina and zirconia.

The piezoelectric element 174 is formed on the vibration plate 176 at a position corresponding to 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, that is, to the right in FIG.

Upper electrode terminal 168 and lower electrode terminal 17
0 are formed on the upper surfaces of the auxiliary electrode 172 and the lower electrode 166, respectively. The lower electrode terminal 170 is in electrical contact with the lower electrode 166, and the upper electrode terminal 168 is in electrical contact with the upper electrode 164 via the auxiliary electrode 172, so that the connection between the piezoelectric element and the outside of the actuator 106 is possible. Transfers signals. The upper electrode terminal 168 and the lower electrode terminal 170 have a height equal to or higher than the height of the piezoelectric element 174 in which the electrodes 164 and 166 and the piezoelectric layer 160 are combined.

FIG. 17 shows a method of manufacturing the actuator 106 shown in FIG. First, the green sheet 40
The through hole 40 is formed by pressing or laser processing.
Perforate a. The green sheet 40 is formed on the substrate 1 after firing.
78. The green sheet 40 is formed of a material such as ceramic.

Next, another green sheet 41 is laminated on the surface of the green sheet 40. Green sheet 41
After firing, the diaphragm 176 is formed. The green sheet 41 is formed of a material such as zirconia oxide.

Next, on the surface of the green sheet 41, the conductive layer 42, the piezoelectric layer 160, and the conductive layer 44 are sequentially formed by a method such as pressure film printing. The conductive layer 42 is formed later by the lower electrode 166.
The conductive layer 44 will later become the upper electrode 164
It is what becomes.

Next, the formed green sheet 40, green sheet 41, conductive layer 42, piezoelectric layer 160 and conductive layer 44 are dried and fired.

The spacer members 47 and 48 are members for raising the heights of the upper electrode terminal 168 and the lower electrode terminal 170 to be higher than the piezoelectric element. Spacer member 47,
48 is formed by printing or laminating the same material as the green sheets 40 and 41. Spacer members 47, 48
Is used, the upper electrode terminal 168 which is a noble metal is used.
In addition, the material of the lower electrode terminal 170 can be reduced. Also,
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 set with high accuracy.

When the connection portion 44 'with the conductive layer 44 and the spacer members 47 and 48 are formed at the same time when the conductive layer 42 is formed, the upper electrode terminal 168 and the lower electrode terminal 170 can be easily formed or firmly fixed. be able to. Finally, an upper electrode terminal 168 and a lower electrode terminal 170 are formed in end regions of the conductive layers 42 and 44. When forming the upper electrode terminal 168 and the lower electrode terminal 170, the upper electrode terminal 168 and the lower electrode terminal 170
It is formed so as to be electrically connected to 60.

FIG. 18 shows still another embodiment of the ink cartridge to which the present invention is applied. FIG. 18 (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. 18B shows a detailed cross section of the actuator 650 and the through hole 1c shown in FIG. FIG. 18C illustrates a plane of the actuator 650 and the through hole 1c illustrated in FIG. 18B. 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. Since the through-hole 1c is formed at a position facing the actuator 650, a minimum amount of ink is secured in the through-hole 1c. Therefore, the ink end of the container 1 can be reliably detected 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.

FIG. 19 shows another embodiment of the through hole 1c. In each of FIGS. 19A, 19B, and 19C, the left side diagram shows a state where the ink K does not exist 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. 18, the side surface of the through hole 1c is formed as a vertical wall. In FIG. 19A, the side surface 1d of the through hole 1c is oblique in the vertical direction and is enlarged and opened outward. In FIG. 19B, the steps 1e and 1f are formed on the side surface of the through hole 1c, and the upper step 1f is wider than the lower step 1e. In FIG. 19C, 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. 19A to 19C, the amount of the ink K in the ink reservoir can be reduced. Therefore, M′cav described in FIG. 1 and FIG.
It can be smaller than M'max. For this reason, the vibration characteristic of the actuator 650 at the time of ink end can be made significantly different from that at the time of ink remaining where a printable amount of ink K remains in the container 1, and the ink end can be detected more reliably. it can.

FIG. 20 is a perspective view showing another embodiment of the actuator. The actuator 660 has a packing 76 outside the through hole 1c of the diaphragm 72 constituting the actuator 660. Actuator 660
A crimping hole 77 is formed on the outer periphery of the hole. The actuator 660 is fixed to the container 1 by swaging via the swaging hole 77.

FIGS. 21A and 21B 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 technique such as etching, and a piezoelectric element 82 is mounted on the other surface. The bottom of the concave portion 81 in the concave portion forming substrate 80 functions as a vibration region. Therefore, the vibration region of the actuator 670 is defined by the peripheral edge of the concave portion 81.

The structure of the actuator 670 is similar to that of the actuator 106 according to the embodiment shown in FIG. 1 except that the substrate 178 and the vibration plate 176 are integrally formed.
In this case, the manufacturing process when manufacturing the ink cartridge can be shortened, and the cost is reduced. The actuator 670 preferably 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. Incidentally, the actuator 106 according to the embodiment of FIG.
Similar to the actuator 670 according to the embodiment of FIG.
It may be formed so that it can be embedded in the through hole 1c.

FIG. 22 is a perspective view showing a structure in which the actuator 106 is integrally formed as the mounting module body 100. The module 100 is mounted at a predetermined position on the container 1 of the ink cartridge. Module body 100
Is configured to detect a state of consumption 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 includes a base 102 having a substantially rectangular flat surface, and a columnar portion 1 on the base 102 that accommodates an actuator 106 oscillated by a drive signal.
16. In addition, the module body 100
When mounted on the ink cartridge, the actuator 106 of the module 100 is configured so as not to contact from the outside. Thereby, the actuator 1
06 can be protected from external contact. In addition, the tip side edge of the cylindrical portion 116 is rounded, so that the cylindrical portion 116 can be easily fitted into a hole formed in the ink cartridge.

FIG. 23 shows the module 1 shown in FIG.
FIG. The module body 100 includes a liquid container mounting portion 101 made of resin, a piezoelectric device mounting portion 105 having a plate 110 and a concave portion 113 (see FIG. 22).
And 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.

Column 1 included in liquid container mounting portion 101
16 and the base 102 are connected to the lead wires 104a and 1a.
An opening 114 is formed at the center so as to be able to accommodate the actuator 106 and the film 10.
8 and opening 11 to accommodate plate 110
4, a recess 113 is formed.

The actuator 106 includes a plate 110
The plate 110 and the actuator 106 are fixed to the concave portion 113 (the liquid container mounting portion 101). Therefore, the lead wire 104
a and 104b, actuator 106, film 10
8 and the plate 110 are integrally mounted on the liquid container mounting portion 101.

The lead wires 104a and 104b are coupled to the upper and lower electrodes of the actuator 106, respectively, to transmit a drive signal to the piezoelectric layer, while transmitting a signal of the resonance frequency detected by the actuator 106 to a recording device or the like. .

The actuator 106 is connected to the lead wire 1
It oscillates temporarily based on the drive signals transmitted from 04a and 104b. Also, the actuator 106
Oscillates after oscillation and generates a back electromotive force by the oscillation. At this time, the resonance frequency corresponding to the consumption state of the liquid in the liquid container can be detected by detecting the oscillation period of the back electromotive force waveform.

[0253] The film 108 is
And the plate 110 are adhered 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. By fixing the actuator 106 and the plate 110 to each other with a film 108 in a planar shape, there is no variation due to the bonding location, and portions other than the vibrating portion do not vibrate. Therefore, the actuator 106 is connected to the plate 11
Even if it is adhered to zero, the vibration characteristics of the actuator 106 do not change.

The plate 110 has a circular shape, and the opening 114 of the base 102 is formed in a cylindrical shape. The actuator 106 and the film 108 are formed in a rectangular shape. Lead wires 104a and 104b, actuator 106, film 108 and plate 110
May be detachable from the base 102. Base 1
02, the lead wires 104a and 104b, the actuator 106, the film 108, and the plate 110 are arranged symmetrically with respect to the central axis of the module body 100. The centers of the base 102, the actuator 106, the film 108, and the plate 110 are the module 1
00 is substantially on the central axis.

The area of the opening 114 of the base 102 is formed to be larger than the area of the vibration area of the actuator 106. At the position facing the vibrating part of the actuator 106 at the center of the plate 110, a through-hole 112
Are formed. As shown in FIGS. 1 and 2, 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, it is preferable that the depth of the through hole 112 is equal to or less than one third of its diameter. The through-hole 112 has a substantially perfect circular shape symmetric with respect to the central axis of the module body 100. Also, 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 is
The shape may be a taper shape or a step shape. The module 100 is mounted on the side, top, or bottom of the container 1 such that the through-hole 112 faces the inside of the container 1. When the ink is consumed and the ink around the actuator 106 runs out, a change in the ink level can be detected based on a large change in the resonance frequency of the actuator 106.

FIG. 24 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. The liquid container mounting portion 401 includes a base 402 having a square shape with a substantially rounded plane, and a cylindrical column portion 403 on the base 402. Further, the piezoelectric device mounting portion 405 is provided with a plate-shaped element 406 erected on the cylindrical portion 403.
And a recess 413. The actuator 106 is vertically arranged in a concave portion 413 provided on the side surface of the plate-shaped element 406. 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. 25 shows the module 4 shown in FIG.
It is an exploded perspective view of 00. Similar to the module 100 shown in FIG. 22, the module 400 includes a liquid container mounting portion 401 and a piezoelectric device mounting portion 405. The liquid container mounting portion 401 has a base 402 and a columnar portion 403,
The piezoelectric device mounting portion 405 includes the plate-shaped element 406 and the concave portion 41.
3 The actuator 106 includes a plate 410
And is fixed to the concave portion 413. Module body 4
00 further includes lead wires 404a and 404b, actuator 106, and film 408.

In the present embodiment, the plate 410 has a rectangular shape, and the opening 41 provided in the plate-like element 406 is provided.
4 is also formed in a rectangular shape. Lead wires 404a and 404b, actuator 106, film 408,
The plate 410 may be configured to be detachable from the base 402. The actuator 106, the film 408, and the plate 410 are arranged symmetrically with respect to a central axis passing 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,
It is preferable to set the size to one third or less of the diameter of No. 12. 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 body 400 has a through hole 41
2 can be mounted on the bottom of the container 1 so that it is located inside the container 1. Since the actuator 106 is disposed in the container 1 so as to extend in the vertical direction, the base 40
By changing the height at which the actuator 106 is disposed in the container 1 by changing the height of the ink container 2, the setting at the time of ink end can be easily changed.

FIG. 26 shows still another embodiment of the module. Similarly to the module 100 shown in FIG. 22, the module 500 shown in FIG. 26 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
1 includes a base 502 having an opening 514 formed in the center thereof for accommodating the lead wires 504a and 504b, and a recess around the opening 514 for accommodating the actuator 106, the film 508, and the plate 510. 513 are formed. The actuator 106 is
It is fixed to the piezoelectric device mounting portion 505 via the plate 510. Therefore, the lead wires 504a and 504b,
Actuator 106, film 508 and plate 5
10 is integrally attached to the liquid container attachment portion 501.

In the module 500 of the present embodiment, a cylindrical base 503 whose upper surface is inclined in the up-down direction is formed on a square base 502 having a plane with a substantially rounded corner. Column part 50
The actuator 106 is disposed on a concave portion 513 that is provided obliquely in the vertical direction on the upper surface of the actuator 3.

That is, the distal end 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 disposed so as to be inclined with respect to the vertical direction of the container 1.
It is desirable that the inclination angle of the distal end of the module body 500 be approximately between 30 ° and 60 ° in consideration of detection performance.

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. 27 shows the module 1 shown in FIG.
FIG. 4 is a cross-sectional view of the vicinity of 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. In order to be able to seal with the O-ring as described above, it is preferable that the module body 100 includes the columnar portion described with reference to 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 part of the actuator 106 are liquid or gas, the ink consumption state can be detected using the module 100.

In addition to the module 100, FIG.
The module 400 shown in FIG. 4, the module 500 shown in FIG. 26, or the modules 700A, 700B, 750A, and 750B shown in FIGS. 28 and 29, and the mold structure 600 are mounted on the container 1, The presence or absence of ink may be detected.

FIG. 28 shows still another embodiment of the module body 100. Module body 750A in FIG.
Has an actuator 106b and a base 360. The module body 750A is mounted on the container 1 such that the front surface is substantially integrated with the inner surface of the side wall of the container 1. The actuator 106b includes a piezoelectric layer 160, an upper electrode 164, a lower electrode 166, and a vibration plate 176.
A lower electrode 166 is formed on the upper surface of diaphragm 176. The piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and the upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Therefore, the piezoelectric layer 160 is formed so as to be sandwiched between the upper electrode 164 and the lower electrode 166 from above and below. 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. Piezoelectric element and diaphragm 176
Is a vibrating section where the actuator actually vibrates. A through hole 385 is provided in the side wall of the container 1. Therefore, the ink comes into contact with the vibration plate 176 through the through hole 385 of the container 1.

Next, the module 7 shown in FIG.
The operation of 50A will be described. The upper electrode 164 and the lower electrode 166 transmit a drive signal to the piezoelectric layer 160 and transmit a signal of the resonance frequency detected by the piezoelectric layer 160 to the recording device. The piezoelectric layer 160 oscillates by a drive signal transmitted by the upper electrode 164 and the lower electrode 166, and then vibrates residually. Due to the residual vibration, the piezoelectric layer 160 generates a back electromotive force. The presence or absence of ink can be detected by counting the oscillation period of the back electromotive force waveform and detecting the resonance frequency at that time.

In the module body 750A, only the surface of the vibrating portion of the actuator 106b opposite to the piezoelectric element side, that is, as shown in FIG.
The ink comes into contact with the ink in the ink container 1.
In the module body 750A of FIG. 28A, the lead wires (104a, 104b,
The electrodes 04a, 404b, 504a and 504b) need not be embedded in the module. For this reason, the molding process is simplified. Further, replacement and recycling of the module body 750A become possible. Further, since the actuator 106b is protected by the base 360,
The actuator 106b can be protected from contact with the outside.

FIG. 28B shows another embodiment of the module. Module body 750B in FIG.
Has an actuator 106b and a base 360. The module body 750B is mounted on the container 1 such that the front surface is substantially integral with the inner surface of the side wall of the container 1. The actuator 106b includes a piezoelectric layer 160, an upper electrode 164, a lower electrode 166, and a vibration plate 176.
A lower electrode 166 is formed on the upper surface of diaphragm 176. The piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and the upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Therefore, the piezoelectric layer 160 is formed so as to be sandwiched between the upper electrode 164 and the lower electrode 166 from above and below. 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. Piezoelectric element and diaphragm 176
Is a vibrating section where the actuator actually vibrates. A thin wall portion 380 is provided on a side wall of the container 1. The module 750B is connected to the actuator 106b.
The surface of the vibrating portion opposite to the piezoelectric element side, that is, FIG.
As shown in (B), only the vibration plate 176 is mounted on the ink container 1 so as to contact the thin wall portion 380 of the ink container 1. Therefore, the vibrating part of the actuator 106b
Residual vibration occurs with the thin wall portion 380.

Next, the module 7 shown in FIG.
The operation of 50B will be described. The upper electrode 164 and the lower electrode 166 transmit a drive signal to the piezoelectric layer 160 and transmit a signal of the resonance frequency detected by the piezoelectric layer 160 to the recording device. The piezoelectric layer 160 oscillates according to the drive signal transmitted by the upper electrode 164 and the lower electrode 166, and then vibrates at a resonance cycle. The diaphragm 176 is the container 1
Contact with the thin wall portion 380 of the actuator 1
The vibrating portion 06b vibrates residually together with the thin wall portion 380.
Since the inner side of the container 1 of the thin wall portion 380 comes into contact with the ink, when the actuator 106b vibrates with the thin wall portion 380, the resonance frequency and amplitude of the residual vibration change depending on the remaining amount of ink. Due to the residual vibration, the piezoelectric layer 160 generates a back electromotive force. The ink remaining amount can be detected by counting the oscillation period of the back electromotive force waveform and detecting the resonance frequency at that time.

In the module body 750B of FIG. 28B, the lead wires (104) shown in FIGS.
a, 104b, 404a, 404b, 504a and 50
The electrode 4b) need not be embedded in the module. For this reason, the molding process is simplified. Further, replacement and recycling of the module body 750B can be performed. Further, since the actuator 106b is protected by the base 360, the actuator 106b can be protected from contact with the outside.

FIG. 29A is a sectional view of the ink container when the module 700B is mounted on the container 1. FIG. In the case of FIG. 29A, a module 700B is used as one of the mounting structures. The module 700B is mounted on the container 1 such that the liquid container mounting portion 360 protrudes into the container 1. A through hole 370 is formed in the mounting plate 350, and the through hole 370 faces the vibrating portion of the actuator 106b. Further, a hole 382 is formed in the bottom wall of the module 700B, and a piezoelectric device mounting portion 363 is formed. Actuator 106b
Are provided so as to close the holes 382.

Therefore, the ink is supplied to the piezoelectric device mounting portion 3.
63 holes 382 and mounting plate 350 through holes 370
, And contacts the diaphragm 176. Piezoelectric device mounting part 3
63 holes 382 and mounting plate 350 through holes 370
Together form an ink reservoir. Piezoelectric device mounting part 363
And the actuator 106b are fixed by a mounting plate 350 and a film member. Further, a sealing structure 372 is provided at a connection portion between the liquid container mounting portion 360 and the container 1. The sealing structure 372 is
It may be formed of a plastic material such as a synthetic resin,
It may be formed by an O-ring. Although the module 700B of FIG. 29A and the container 1 are separate bodies, FIG.
As shown in (B), the piezoelectric device mounting portion of the module 700B may be constituted by a part of the container 1.

In the module 700B of FIG. 29A, it is not necessary to embed the lead wires shown in FIGS. 22 to 26 into the module. For this reason, the molding process is simplified. Further, the module 700B can be replaced, and the module 700B can be recycled.

When the ink cartridge swings, the ink can adhere to the upper surface or the side surface of the container 1. Such ink drips from the top or side surface of the container 1 and contacts the actuator 106b,
May malfunction. However, the module 7
When the liquid container mounting portion 360 of 00B protrudes into the container 1, the actuator 106b does not malfunction due to ink dripping from the upper surface or side surface of the container 1.

In the example of FIG. 29A, the diaphragm 17
6 and only a part of the mounting plate 350 are mounted on the container 1 so as to be in contact with the ink in the container 1.

FIG. 29B shows the state of the actuator 106b.
FIG. 4 is a cross-sectional view of another example of the ink container when the ink container is mounted on the container 1. In the ink cartridge according to the example of FIG. 29B, the protection member 361 is
It is attached to the container 1 separately from b. Therefore, the protection member 361 and the actuator 106b are not integrated as a module. However, the protection member 361 can protect the actuator 106b from being touched by the user. A hole 380 is formed in the side wall of the container 1 corresponding to the front surface of the actuator 106b.
Are arranged.

The actuator 106b includes the piezoelectric layer 16
0, an upper electrode 164, a lower electrode 166, a diaphragm 176, and a mounting plate 350. Mounting plate 35
A vibration plate 176 is formed on the upper surface of the lower electrode 0, and a lower electrode 166 is formed on the upper surface of the vibration plate 176. Then, the piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and the piezoelectric layer 16
The upper electrode 164 is formed on the upper surface of the “0”. 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. Piezoelectric layer 160, upper electrode 164
The circular portion that is the main portion of each of the lower electrode 166 and the lower electrode 166 forms 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 is provided with a through hole 370. Therefore, the ink is supplied to the diaphragm 176 through the hole 380 of the container 1 and the through hole 370 of the mounting plate 350.
Contact with. Hole 380 of container 1 and mounting plate 350
Through holes 370 together form an ink reservoir. Also,
In the example of FIG. 29B, the actuator 106b is protected from contact with the outside by the protection member 361.

Incidentally, the actuator 106b and the mounting plate 350 in the examples of FIGS.
It can be replaced by the actuator 106 having the substrate 178 of FIG. FIG. 29C shows the state of the actuator 106b.
An embodiment comprising a mold structure 600 including:
In the example of FIG. 29C, a mold structure 600 is used as one of the mounting structures. The mold structure 600 includes:
It has an actuator 106b and a mold part 364. The actuator 106b and the mold part 364 are
It is molded integrally. The mold section 364 is formed of a plastic material such as a silicone resin. The mold part 364 is formed to have two legs extending from the actuator 106b side. The foot part of the mold part 364 has a lead wire 362 inside. In order to fix the mold portion 364 and the container 1 in a liquid-tight manner, the ends of the two legs of the mold portion 364 are connected to the container 1.
Is formed hemispherically outside. Mold part 364
Is mounted on the container 1 so that the actuator 106 b projects into the container 1. Thereby, the vibrating part of the actuator 106b comes into contact with the ink in the container 1. The upper electrode 164, the piezoelectric layer 160, and the lower electrode 166 of the actuator 106b are
Protected from contact with ink.

A mold structure 600 shown in FIG.
Sealing structure 37 between mold part 364 and container 1
The ink does not easily leak from the container 1 without requiring the ink container 2.
In addition, since the mold structure 600 does not protrude from the outside of the container 1, the actuator 106b can be protected from contact with the outside. Further, in the mold structure 600, since the mold portion 364 protrudes into the container 1, the actuator 106b does not malfunction due to ink dripping from the upper surface or side surface of the container 1.

FIG. 30 shows the actuator 1 shown in FIG.
6 shows an embodiment of an ink cartridge and an ink jet recording apparatus using No. 06. Multiple ink cartridges 1
Reference numeral 80 is attached to an ink jet 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, different colors. The actuator 106 as a means for detecting at least acoustic impedance is provided on the bottom surface of each of the plurality of ink cartridges 180.
Is installed. By mounting the actuator 106 on the ink cartridge 180, the remaining amount of ink in the ink cartridge 180 can be detected.

FIG. 31 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.

[0284] The ink introduction section 182 is connected to the air supply port 181.
And an ink inlet 183. Air supply port 181
Supplies air to the ink cartridge 180. Ink is introduced from the ink cartridge 180 into the ink introduction port 183.

The ink cartridge 180 has an air inlet 185 and an ink supply port 187. Air inlet 1
85 is supplied with air from the air supply port 181 of the ink introduction unit 182. The ink supply port 187 supplies ink to the ink introduction port 183 of the ink introduction section 182. By introducing air from the air introduction port 185 to the ink cartridge 180, the supply of ink from the ink cartridge 180 to the ink introduction unit 182 is promoted. The holder 184 communicates the ink supplied from the ink cartridge 180 via the ink introduction unit 182 to the head plate 186.

FIG. 32 shows another embodiment of the ink cartridge 180 shown in FIG. In the ink cartridge 180A shown in FIG. 32A, the actuator 106 is mounted on a bottom surface 194a formed obliquely in the vertical direction. Since the actuator 106 is mounted obliquely with respect to the vertical direction of the ink container 194, the ink can be swept well.

[0287] Ink container 1 of ink cartridge 180
Inside the 94, a wave barrier 192 is provided at a predetermined height from the inner bottom surface of the ink container 194 at a position facing the actuator 106. A gap filled with ink is formed between the actuator 106 and the break wall 192. 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, and the shock may cause gas or air bubbles to be detected by the actuator 106, causing the actuator 106 to malfunction. However, by providing the wave preventing wall 192, the wave of ink near the actuator 106 can be prevented, and the 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 be mounted at the center of the ink container 194 in the width direction.

Since the ink is supplied to the outside through the ink supply port 187, by providing the actuator 106 near the ink supply port 187, the ink and the actuator 106 are surely brought into contact with each other until the ink near end. Therefore, the actuator 106 can reliably detect the time point 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 point on the carriage is ensured. Become. The reason is that the most important connection between the ink container and the carriage is a reliable connection between the ink supply port and the supply needle. If there is any deviation between them, the tip of the supply needle will be damaged, or a sealing structure such as an O-ring will be damaged, and ink will leak out. In order to prevent such a problem, an ink jet printer usually has a special structure that enables 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 ensured at the same time. Further, by mounting the actuator 106 at the center in the width direction of the ink container 194, more reliable alignment can be realized. This is because, when the ink container is pivoted about the center line in the width direction when the ink container is mounted on the holder, the pivoting is the least.

FIG. 33 shows still another embodiment of the ink cartridge 180. FIG. 33A is a sectional view of the ink cartridge 180C, and FIG.
The side wall 19 of the ink cartridge 180C shown in FIG.
FIG. 33C is an enlarged sectional view of FIG. 4B, and FIG. 33C is a perspective view from the front.

In the ink cartridge 180C, the semiconductor storage means 7 and the actuator 106 are formed on the same circuit board 610. FIG. 33 (B) and FIG.
As shown in (C), the semiconductor storage means 7 is a circuit board 61.
0, and the actuator 106 is formed below the semiconductor storage means 7 on the same circuit board 610.

A modified O-ring 614 is mounted on the side wall 194b so as to surround the periphery of the actuator 106. The circuit board 610 is attached to the ink container 1 on the side wall 194b.
A plurality of caulking portions 616 for joining to 94 are formed. The circuit board 610 is joined to the ink container 194 via the caulking portion 616, and the odd-shaped O-ring 614 is attached to the circuit board 6
By pressing the ink cartridge against the ink cartridge 10, the vibrating area of the actuator 106 can be brought into contact with the ink, while keeping the outside and the inside of the ink cartridge liquid-tight.

A terminal 612 is formed in the semiconductor storage means 7 and in the vicinity of the semiconductor storage means 7. Terminal 612 is
Signals are exchanged between the semiconductor storage means 7 and the outside such as an inkjet storage device. The semiconductor storage means 7 can 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 information on ink such as the remaining amount of ink detected by the actuator 106. Further, the semiconductor storage means 7
Information on characteristic parameters such as characteristics of the ink and the ink cartridge used when detecting the remaining amount of ink and the like is stored.

The semiconductor storage means 7 stores the ink container 19 in advance.
4 is full, that is, the ink is in the ink container 1
The resonance frequency when the ink is filled in the ink tank 94 or when the ink is at the end, that is, when the ink in the ink container 194 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. Also, the resonance frequency of the ink in the ink container 194 in the full or end state may be stored during the manufacture of the ink container 194.

The ink container 194 is stored in the semiconductor storage means 7 in advance.
By storing the resonance frequency when the ink inside is full or at the end, and reading out the data of the resonance frequency on the ink jet recording apparatus side, it is possible to correct variations in detecting the remaining amount of ink. This makes it possible to accurately detect that the remaining amount of ink has decreased to the reference value.

FIG. 34 shows still another embodiment of the ink cartridge 180. The ink cartridge 180D shown in FIG. 34A has a side wall 194b of the ink container 194.
Are mounted with a plurality of actuators 106. FIG.
The plurality of integrally formed actuators 106 shown in FIG.
Is preferably used as each of the plurality of actuators 106. The plurality of actuators 106
It is arranged on the side wall 194b with an interval in the vertical direction. By arranging the plurality of actuators 106 on the side wall 194b at intervals in the vertical direction, the remaining amount of ink can be detected stepwise.

The ink cartridge 1 shown in FIG.
In 80E, an actuator 606 that is long in the vertical direction is mounted on the side wall 194b of the ink container 194. The ink container 1 is moved by the vertically long actuator 606.
A change in the remaining amount of ink in 94 can be detected continuously. Preferably, the length of the actuator 606 is at least half the height of the side wall 194b. FIG.
The actuator 606 in FIG.
Has a length from approximately the upper end to approximately the lower end.

The ink cartridge 1 shown in FIG.
80F is the ink cartridge 1 shown in FIG.
Similar to 80D, a plurality of actuators 106 are mounted on the side wall 194b of the ink container 194. Further, a break 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 the plurality of actuators 106 integrally formed as shown in FIG. 14 as each of the plurality of actuators 106.

[0302] A gap filled with ink is formed between the actuator 106 and the wave preventing 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.

[0303] When the ink container 194 rolls, a wave of ink is generated inside the ink container 194, and gas or air bubbles are detected by the actuator 106 due to the impact, and the actuator 106 may malfunction. However, by providing the wave preventing wall 192 as shown in FIG. 34C, it is possible to prevent the ink from waving around the actuator 106 and prevent the actuator 106 from malfunctioning. Further, the wave preventing wall 192 prevents bubbles generated by the swinging of the ink from entering the actuator 106.

FIG. 35 shows still another embodiment of the ink cartridge 180. The ink cartridge 180G in FIG. 35A has a plurality of partition walls 212 extending downward from the upper surface 194c of the ink container 194. A predetermined distance is provided between the lower end of each partition 212 and the bottom surface of the ink container 194, and the bottom of the ink container 194 is in communication. The ink cartridge 180G includes a plurality of partition walls 2.
A plurality of accommodation rooms 213 partitioned by each of 12
Having. The bottoms of the plurality of storage chambers 213 communicate with each other.

In each of the plurality of accommodation rooms 213,
The actuator 10 is mounted on the upper surface 194c of the ink container 194.
6 is mounted. The integrally molded actuator 106 shown in FIG.
06 is preferably used. The actuator 106 is provided on the upper surface 1 of the accommodation chamber 213 of the ink container 194.
It is arranged substantially at the center of 94c.

The capacity of the storage chamber 213 is
7 is the largest, and gradually decreases as the distance from the ink supply port 187 to the depth of the ink container 194 increases. Therefore, the intervals at which the actuators 106 are arranged are also wider on the ink supply port 187 side, and
7, the distance from the ink container 194 to the depth of the ink container 194 becomes smaller.

[0307] Ink is discharged from the ink supply port 187, and air enters from the air introduction port 185. For this reason, the ink in the storage chamber 213 at the back of the ink cartridge 180G is consumed in order from the ink in the storage chamber 213 on the ink supply port 187 side. For example, the ink in the storage chamber 213 closest to the ink supply port 187 is consumed and the ink supply port 1 is consumed.
While the water level of the ink in the storage chamber 213 closest to 87 is falling, the other storage chambers 213 are filled with ink. When the ink in the storage chamber 213 closest to the ink supply port 187 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 is consumed. For the first time, 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.
Is 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.

[0308] 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,
Since the capacity of the storage chamber 213 gradually decreases from the ink supply port 187 to the back, the actuator 1
The time interval for detecting the decrease of the ink amount by 06 gradually decreases, and the frequency can be detected more frequently as the ink end is approached.

The ink cartridge 180 shown in FIG.
H has one partition 212 extending downward from the upper surface 194c of the ink container 194. A predetermined interval is provided between the lower end of the partition 212 and the bottom surface of the ink container 194,
The bottom of the ink container 194 is in communication. The ink cartridge 180H has two storage chambers 213a and 213b partitioned by the partition 212. Accommodation room 213
The bottoms of a and 213b communicate with each other.

The capacity of the storage chamber 213a on the ink supply port 187 side is equal to the capacity of the storage chamber 2
13b. In particular, it is preferable that the capacity of the accommodation room 213b is smaller than half of 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 the ink container 19.
4 is formed as a groove extending upward from the side wall 194b. The buffer 214 captures air bubbles that have entered the ink storage chamber 213b. Therefore, it is possible to prevent the actuator 106 from erroneously recognizing the ink end due to bubbles.

Note that the actuator 106 is moved
3b, the ink amount from the detection of the ink near end to the complete ink end state corresponds to the ink consumption state in the storage chamber 213a grasped by the dot counter. By performing the correction, the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length or interval of the partition 212, the amount of ink that can be consumed after the detection of the ink near end can be changed.

The ink cartridge 180 shown in FIG.
I is the one in which the porous member 216 is filled in the storage chamber 213b of the ink cartridge 180H in FIG. The porous member 216 is installed so as to fill the entire space from the upper surface to the lower surface in the storage chamber 213b, and is in contact with the actuator 106.

When the ink container falls down or reciprocates 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, since the porous member 21 catches air,
Contact between the actuator 106 and air can be prevented. Further, since the porous member 216 also holds ink, even when the ink container shakes, it is possible to prevent the ink from being applied to the actuator 106 and the actuator 106 from erroneously detecting absence of ink as presence of ink. The porous member 216 is provided in the accommodation room 21 having the smallest capacity.
3 is preferable.

Note that the actuator 106 is moved
3b, the ink amount from the detection of the ink near end to the complete ink end state corresponds to the ink consumption state in the storage chamber 213a grasped by the dot counter. By performing the correction, the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length or interval of the partition 212, the amount of ink that can be consumed after the detection of the ink near end can be changed.

The ink cartridge 180 shown in FIG.
J indicates that the porous member 216 of the ink cartridge 180I in FIG. 35C has two types of porous members 2 having different pore diameters.
16A and 216B. 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 may be formed of a member having a lower liquid affinity than the porous member 216B.

[0317] Since the porous member 216B having a smaller pore diameter has a larger capillary force than the porous member 216A having a larger pore diameter, the ink in the storage chamber 213b is not filled with the lower porous chamber member 21A.
6B and are held. Therefore, once air reaches the actuator 106 and the actuator 10
When No. 6 detects that there is no ink, the ink does not reach the actuator again and the actuator 106 does not detect that there is ink. Further, since the ink is absorbed by the porous member 216B farther from the actuator 106,
The ink in the vicinity of the actuator 106 is good. Therefore, the amount of change in acoustic impedance change when detecting the presence or absence of ink becomes large.

Note that the actuator 106 is
3b, the ink amount from the detection of the ink near end to the complete ink end state corresponds to the ink consumption state in the storage chamber 213a grasped by the dot counter. By performing the correction, the ink can be consumed to the end. Further, by adjusting the capacity of the storage chamber 213b by changing the length or 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. 36A is a sectional view showing an ink cartridge 180K which is an embodiment in which the ink cartridge 180I shown in FIG. 35C is modified. FIG.
The lower part of the porous member 216 of the ink cartridge 180K shown in (A) is designed so as to be gradually reduced toward the bottom surface of the ink container 194 so that the horizontal cross-sectional area and the hole diameter are reduced. ing. FIG.
As shown in (A), the ink cartridge 180K
A rib is provided on the side wall to compress the lower part of the porous member 216 so that the hole diameter becomes smaller. Since the pore diameter of the lower portion of the porous member 216 is reduced by being compressed, the ink is collected and held at the lower portion of the porous member 216. Since the ink is absorbed in the lower portion of the porous member 216 far from the actuator 106, the ink in the vicinity of the actuator 106 can be easily removed. Therefore, the amount of change in acoustic impedance change when detecting the presence or absence of ink becomes large. Accordingly, it is possible to prevent the ink from swaying and the ink being applied to the actuator 106 mounted on the upper surface of the ink cartridge 180K, and the actuator 106 from erroneously detecting the absence of the ink as the presence of the ink.

On the other hand, in the ink cartridge 180L shown in FIGS. 36B and 36C, the lower portion of the porous member 216 has the ink container 19L in the width direction of the ink container 194.
4 is gradually reduced toward the bottom surface of the ink container 194, so that the horizontal cross-sectional area and the hole diameter gradually decrease toward the bottom surface of the ink container 194. Porous member 216
Since the pore size of the lower portion is reduced by being compressed, the ink is collected at the lower portion of the porous member 216,
Will be retained. Since the ink is absorbed in the lower part of the porous member 216B far from the actuator 106, the ink in the vicinity of the actuator 106 can be easily removed. Therefore, the amount of change in acoustic impedance change when detecting the presence or absence of ink becomes large. Therefore, it is possible to prevent the ink from swaying and causing the ink to be applied to the actuator 106 mounted on the upper surface of the ink cartridge 180L, thereby preventing the actuator 106 from erroneously detecting the absence of ink as the presence of ink.

FIG. 37A shows still another embodiment of the ink cartridge using the actuator 106.
The ink cartridge 220A of FIG. 37A has a first partition 222 provided to extend downward from the upper surface of the ink cartridge 220A. First partition 22
A predetermined space is provided between the lower end of the ink cartridge 220 and the bottom surface of the ink cartridge 220A, and 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 with respect to the first partition 222, the ink cartridge 22
A second partition 224 is formed to extend above the bottom surface of 0A. A predetermined space is provided between the upper end of the second partition 224 and the upper surface of the ink cartridge 220A, so that 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 225a at the back of the first partition 222 when viewed from the ink supply port 230. On the other hand, the second partition 224 forms a second storage chamber 225 b in front of the second partition 224 when viewed from the ink supply port 230. The capacity of the first storage chamber 225a is larger than the capacity of the second storage chamber 225b. The first partition wall 222 and the second partition wall 224 are spaced apart from each other so as to cause capillary action, that is, a capillary channel 227 is formed. Therefore, the first
Is collected in the capillary channel 227 by the capillary force of the capillary channel 227. For this reason, 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 in the second accommodation room 22.
5b, the first storage chamber 225
After the ink in a is consumed, the ink in the second storage chamber 225b is consumed.

Then, the side wall of the ink cartridge 220A on the ink supply port 230 side, that is, the second storage chamber 2
The actuator 106 is mounted on the side wall 25b on the side of the ink supply port 230. The actuator 106 is
The ink consumption state in the second storage chamber 225b is detected. 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 time 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 at what point the remaining amount of ink is used as the ink end.

[0324] The first storage chamber 225 is provided via the capillary channel 227.
a, the ink is supplied to the second storage chamber 225 b from the ink cartridge 22.
It is less susceptible to ink sway due to 0A sway.
Therefore, the actuator 106 can more reliably measure the remaining amount of ink. Further, since the capillary channel 227 holds the ink, the ink is prevented from flowing backward from the second storage chamber 225b to the first storage chamber 225a.

A check valve 228 is provided on the upper surface of the ink cartridge 220A. Check valve 228
When the ink cartridge 220A rolls,
This prevents the ink from leaking out of the ink cartridge 220A. Further, the check valve 228 is connected to the ink cartridge 22.
By installing the ink cartridge on the upper surface of the ink cartridge 220A, evaporation of the ink from the ink cartridge 220A can be prevented. When the ink in the ink cartridge 220A is consumed and the negative pressure in the ink cartridge 220A exceeds the pressure of the check valve 228, the check valve 228 is opened and air is sucked into the ink cartridge 220A. As a result, the pressure in the ink cartridge 220A is kept substantially constant.

FIGS. 37 (C) and (D) show a check valve 228.
FIG. 4 is a diagram showing a cross section of details of FIG. Check valve 2 in FIG. 37 (C)
28 has a valve 232 having a blade 232a formed of rubber. The blade 232 a faces the ventilation hole 233 with the outside of the ink cartridge 220. Feather 2
The vent hole 233 is opened and closed by the deformation of 32a. That is, the amount of ink in the ink cartridge 220 decreases, and the negative pressure in the ink cartridge 220 is reduced by the check valve 228.
When the pressure exceeds the pressure, the blade 232a is deformed (opened) inside the ink cartridge 220, and external air is taken into the ink cartridge 220.

The check valve 228 shown in FIG. 37D has a valve 232 and a spring 235 made of rubber. When the negative pressure in the ink cartridge 220 exceeds the pressure of the check valve 228, the valve 232 descends (presses) against the spring 235 (opens), and external air is released from the ink cartridge 22.
Inhaled within 0.

On the other hand, the ink cartridge 220B shown in FIG.
20A, instead of providing a check valve 228, the first
The porous member 242 is disposed in the accommodation chamber 225a of the first embodiment. The porous member 242 is connected to the ink cartridge 220.
B and the ink cartridge 2
This prevents the ink from leaking out of the ink cartridge 220B when the roll 20B rolls.

As described above, with respect to the carriage and the ink cartridge separate from the carriage mounted on the carriage,
The case where the actuator 106 is mounted on the ink cartridge or the carriage has been described. However, the actuator 106 may be mounted on an ink tank integrated with the carriage and mounted on the inkjet recording apparatus together with the carriage. Further, the actuator 106 may be mounted on an off-carriage type ink tank that supplies ink to the carriage via a tube or the like separately from the carriage. Further, the actuator of the present invention may be mounted on a portion corresponding to an ink cartridge of a member in which the recording head and the ink container are integrally exchangeable.

The recording device control units 2000 and 200
2, 2004, 2006, their respective components, and the control device 840c (see FIG. 10) can be configured by a computer system. Here, a program for causing a computer system to realize each of these elements, and a computer-readable recording medium 201 (see FIG. 5) that records the program are also covered by the present invention.

Further, when each of the above-mentioned components is realized by a program such as an OS operating on a computer system, a program including various instructions for controlling the program such as the OS and a recording medium 202 storing the program are also provided. , Is the subject of protection in this case.

Here, the recording media 201 and 202 include those which can be recognized as a single unit such as a floppy disk, and the like.
It also includes a network for transmitting various signals.

[0333] Examples of the liquid include, besides ink,
Glue, nail polish, etc. may be used.

As described above, the present invention has been described using a plurality of embodiments, but 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 is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0335]

According to the present invention, since the influence of noise on the back electromotive force signal is determined by the noise influence determination unit, the liquid consumption is detected when it is difficult to accurately detect the liquid consumption state due to the presence of noise, for example. Detection of the state can be stopped, and erroneous detection of the remaining amount of liquid can be avoided.

[Brief description of the drawings]

FIG. 1 is a diagram showing details of an actuator 106. FIG.

FIG. 2 is a diagram showing the periphery of an actuator 106 and its equivalent circuit.

FIG. 3 is a diagram illustrating a relationship between ink density and a resonance frequency of ink detected by an actuator 106.

FIG. 4 is a diagram showing a back electromotive force waveform of the actuator 106.

FIG. 5 shows a configuration of a recording device control unit 2000 that detects a change in acoustic impedance to detect the consumption state of the liquid in the liquid container 1 and controls the inkjet recording device based on the detection result. FIG.

FIG. 6 is a block diagram illustrating a recording apparatus control unit 2002 according to another embodiment.

FIG. 7 is a diagram showing still another embodiment of the printing apparatus control unit 2000 shown in FIG.

FIG. 8 is a diagram showing still another embodiment of the printing apparatus control unit 2004 shown in FIG.

FIG. 9 is a flowchart illustrating an operation procedure of the printing apparatus control unit 2006 illustrated in FIG. 8;

FIG. 10 is a diagram showing a circuit configuration of a measurement circuit section 800.

FIG. 11 is a flowchart illustrating an operation procedure of the noise influence determination unit 880.

FIG. 12 is a diagram showing a circuit configuration of a detection circuit unit 1100.

FIG. 13 is a diagram showing a detailed circuit configuration of a liquid presence / absence determining unit 1000 shown in FIG.

FIG. 14 is a diagram showing another embodiment of the actuator 106.

FIG. 15 is a view showing a cross section of a part of the actuator 106 shown in FIG. 14;

FIG. 16 is a view showing a cross section of the entire actuator 106 shown in FIG. 15;

FIG. 17 is a view illustrating a method of manufacturing the actuator 106 illustrated in FIG. 14;

FIG. 18 is a view showing still another embodiment of the ink cartridge of the present invention.

FIG. 19 is a view showing another embodiment of the through hole 1c.

FIG. 20 is a view showing another embodiment of the actuator 660.

FIG. 21 is a view showing still another embodiment of the actuator 670.

FIG. 22 is a perspective view showing the module body 100.

FIG. 23 is an exploded view showing the configuration of the module 100 shown in FIG.

FIG. 24 is a view showing another embodiment of the module body 100.

FIG. 25 is an exploded view showing the configuration of the module 400 shown in FIG. 24.

FIG. 26 is a view showing still another embodiment of the module body 100.

FIG. 27 is a diagram showing an example of a cross section in which the module body 100 shown in FIG.

FIG. 28 is a view showing still another embodiment of the module body 100.

FIG. 29 is a view showing still another embodiment of the module body 100.

FIG. 30 shows the actuator 10 shown in FIGS. 1 and 2
6 is a diagram showing an embodiment of an ink cartridge and an ink jet recording apparatus using No. 6; FIG.

FIG. 31 is a diagram illustrating details of an inkjet recording apparatus.

32 is a diagram showing another embodiment of the ink cartridge 180 shown in FIG.

FIG. 33 is a view showing still another embodiment of the ink cartridge 180.

FIG. 34 is a view showing still another embodiment of the ink cartridge 180.

FIG. 35 is a view showing still another embodiment of the ink cartridge 180.

FIG. 36 is an ink cartridge 1 shown in FIG.
FIG. 28 illustrates another embodiment of the present invention.

FIG. 37 is a view showing still another embodiment of an ink cartridge using the module body 100.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Container 1a Bottom surface 1b Side wall 1c, 40a Through hole 1d Side surface 1e, 1f Step part 1g, 1h Groove 2 Ink supply port 40, 41 Green sheet 42, 44 Conductive layer 44 'Connection part 47, 48 Spacer member 67 Plate 68 Float 71 Adhesive layer 78, 80, 178 Substrate 73, 82, Piezoelectric vibrating plate 74, 75 Ink absorber 76 Packing 77 Caulking hole 81 Depression 100, 400, 500, 700 Module 101, 401, 501 Liquid container mounting part 102 Base 104, 362 Lead wire 105, 405, 505 Piezoelectric device mounting portion 106, 106b, 650, 660, 670 Actuator 108 Film 110 Plate 112, 412, 370 Through hole 113 Recess 114 Opening 116 Columnar portion 160 Piezoelectric layer 162 Cavity 164 Upper electrode 166 Lower electrode 168 Upper electrode terminal 170 Lower electrode terminal 172 Auxiliary electrode 174 Piezoelectric element 176 Vibrating plate 180 Ink cartridge 181 Air supply port 182 Ink introduction section 183 Ink introduction port 184 Holder 185 Air introduction port 186 Head plate 187 Ink supply port 188 Nozzle plate 190 Nozzle 192 Wavebreak wall 194 Ink container 194a Bottom surface 194b Side wall 194c Top surface 212 Partition wall 213, 213a, 213b Storage chamber 214 Buffer 216, 216a, 216b Porous member 220 Ink cartridge 222 First partition 224 Second partition 225a First storage chamber 225b Second storage chamber 227 Capillary channel 228 Check valve 230 Ink supply port 232 Valve 232a Blade 233 Vent hole 235 Spring 242 Porous member 250 Carriage 252 Recording head 254 Ink supply needle 256 Subtank unit 258, 258 'Convex part 260, 260' Elastic wave generating means 262 Ink chamber 266 Membrane valve 270 Valve 272 Ink cartridge 274 Container 274a Bottom surface 274b Side surface 276 Ink supply Port 278 Recess 280, 280 ′ Gelling material 282 Packing 284 Spring 286 Valve 288 Semiconductor storage means 290 Container 290a Bottom surface 292, 294, 296 Ink chamber 298, 300, 302 Ink supply port 304, 306, 308 Gelling material 310, 312, 314 Recess 316 Plate 318 Float 350 Mounting plate 360 Liquid container mounting 364 Mold 372 Sealing structure 402, 502 Base 403, 503 Column 404, 504 Lead wire 408, 508 Film 410, 510 Plate 413, 513 Concave part 414, 514 Opening 600 Mold structure 606 Actuator 610 Circuit board 612 Terminal 800, 802 Measurement circuit 810 NPN transistor 812 PNP transistor 816 Reference potential generator 818 , 820, 828, 830, 832 Resistance 822, 826 Capacitor 824 High-pass filter 834, 840, 842, 844, 846 Terminal 835 Comparator 840c Controller 850, 850A, 850B, 850C Drive voltage generator 860 Amplifier 880 Noise influence determination Unit 900, 902 Digital circuit unit 910, 918 Flip-flop 912, 920 Counter 914, 916 NAND gate 1000, 1002 Liquid presence Constant section 1010 Liquid consumption state correction section 1011 Upper limit value register 1012 Lower limit value register 1014, 1016 Comparison section 1018 AND gate 1020, 1022 Terminal 1100, 1102, 1104 Detection circuit section 1200, 1202, 1210 Liquid consumption state detection section 1300 Head section 1400 Control unit 1402 Recording device operation control unit 1404 Presentation processing unit 1406 Printing operation control unit 1408 Ink replenishment processing unit 1410 Cartridge replacement processing unit 1412 Print data storage processing unit 1414 Print data storage unit 1416 Display 1418 Speaker 1420 Printing operation unit 1422 Ink replenishment device 1424 Cartridge changing device 1432 Cleaning drive unit 1434 Pump 1436 Cleaning unit 1440 Head drive unit 1442 Cleaning Control unit 1444 Information storage control circuit unit 1450 Liquid discharge counter 1452 Liquid consumption correction unit 1500, 1502, 1506 Control circuit unit 2000, 2002, 2004, 2006 Recording device control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 41/18 101D F-term (Reference) 2C056 EA29 EB20 EB29 EB38 EB39 EB44 EB49 EB51 EB56 EB59 EC19 EC23 EC24 EC26 EC39 EC41 EC64 EC67 KB05 KB09 KB11 KC01 KC12 KC13 KC17 KC22 KC27 KC30 KD02 KD06 2F014 AB01 AB02 AB03 CB10

Claims (20)

[Claims] At least a portion is exposed in a storage space for storing a liquid, and a vibrating portion capable of vibrating with respect to the storage space; a vibrating portion can be vibrated based on a drive signal; A piezoelectric element that generates a back electromotive force signal by vibration of the vibrating unit; and a liquid consumption state detection unit that detects a liquid consumption state based on the back electromotive force signal from the piezoelectric element. A liquid consumption state detector comprising a noise influence determination unit that determines the influence of noise on a back electromotive force signal. 2. The liquid consumption state detector according to claim 1, wherein the liquid consumption state detector measures a frequency of the back electromotive force signal. 3. The liquid consumption state detection section has a counter for measuring the number of vibrations of the back electromotive force signal for a predetermined time, and calculates the frequency of the back electromotive force signal based on a numerical value measured by the counter. The liquid consumption state detector according to claim 2, wherein the liquid consumption state detector is configured to measure. 4. The liquid consumption state detecting section has a clock counter for measuring a time during which the back electromotive force signal vibrates a predetermined number of times, and based on the time measured by the clock counter. The liquid consumption state detector according to claim 2, wherein the frequency of the back electromotive force signal is measured. 5. The liquid consumption state detecting section determines that the liquid consumption state cannot be detected when the noise influence determining section determines that the influence of the noise on the back electromotive force signal exceeds a predetermined level. The liquid consumption state detector according to any one of claims 1 to 4, wherein the signal is output. 6. A liquid consumption state detector, comprising: a voltage generator for generating a first reference voltage and a second reference voltage higher than the first reference voltage; and a counter electromotive force signal centered on the first reference voltage. An amplifying unit for amplifying, and a signal amplified by the amplifying unit is Hi with respect to a second reference voltage.
a comparison unit that compares whether the output is gh or low, and wherein the noise influence determination unit determines whether the output of the comparison unit is low and constant in a state before the vibration unit is vibrated based on the drive signal. 6. The liquid consumption according to claim 1, wherein the influence of noise is determined to be small if the output of the comparison unit is not constant, and the influence of noise is determined to be large if the output of the comparison unit is not constant. State detector. 7. A liquid consumption state detecting section, comprising: a voltage generating section for generating a first reference voltage and a second reference voltage lower than the first reference voltage; and a counter electromotive force signal centered on the first reference voltage. An amplifying unit for amplifying, and a signal amplified by the amplifying unit is Hi with respect to a second reference voltage.
and a comparison unit that compares whether the output is gh or low. The noise influence determination unit is configured to determine whether the output of the comparison unit is constant at High in a state before the vibration unit is vibrated based on the drive signal. 6. The liquid consumption according to claim 1, wherein the influence of noise is determined to be small if the output of the comparison unit is not constant, and the influence of noise is determined to be large if the output of the comparison unit is not constant. State detector. 8. The liquid according to claim 1, wherein a portion of the vibrating portion exposed to the liquid storage space has a symmetrical shape when viewed from the liquid storage space side. Consumption state detector. 9. The piezoelectric element is fixed to a position substantially at the center of a portion of the vibrating portion exposed to the liquid accommodating space, on a side opposite to the liquid accommodating space side of the vibrating portion. A liquid consumption state detector according to claim 8. 10. The liquid consumption state detector according to claim 8, wherein a portion of the vibrating portion exposed to the liquid storage space has a circular shape when viewed from an inner surface side of the liquid container. 11. The liquid according to claim 1, wherein a vibration direction of the piezoelectric element is substantially perpendicular to a portion of the vibrating portion exposed to the liquid storage space. Consumption state detector. 12. A liquid container, comprising: a wall for defining a storage space for storing a liquid; and the liquid consumption state detector according to any one of claims 1 to 11. 13. The liquid container according to claim 12, further comprising a storage unit for storing the liquid consumption state detected by the liquid consumption state detector. 14. A liquid, comprising: the liquid container according to claim 12; and a liquid consuming main body connected to the liquid container and consuming the liquid contained in the liquid container. Consumer equipment. 15. A control circuit for controlling a liquid consuming operation of the liquid consuming main body based on the liquid consuming state of the liquid container detected by the liquid consuming state detecting section. 14. The liquid consuming device according to claim 13. 16. A liquid container according to claim 13, connected to the liquid container, a liquid consumption main body for consuming the liquid contained in the liquid container, and a liquid consumption of the liquid container stored in the storage unit. And a control circuit for controlling a liquid consuming operation of the liquid consuming main body based on the state. 17. A control device for controlling a liquid consumption state detector according to claim 1, wherein a drive signal is supplied to the piezoelectric element, and the liquid consumption state detection unit detects the liquid consumption state. Control device. 18. A control device for controlling a liquid consumption state detector according to claim 1, wherein a noise influence judging section judges the influence of noise before giving a drive signal to the piezoelectric element. A control device characterized in that when it is determined that the influence is small, a drive signal is supplied to the piezoelectric element to cause the liquid consumption state detection unit to detect the liquid consumption state. 19. A computer-readable recording medium which is executed by a computer system including at least one computer and records a program for causing the computer system to implement the control device according to claim 17 or 18. 20. An instruction for controlling a second program operating on a computer system including at least one computer, the program being executed by the computer system to control the second program, A computer-readable recording medium on which a program for causing the computer system to implement the control device according to claim 17 or 18 is recorded.