JP2007185933A - Residual liquid amount detection device of liquid container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the amount of a residual liquid and the exhaustion of the liquid by the change of an oscillatory wave of a piezoelectric element which is installed together with a diaphragm in a liquid detection chamber connected to a liquid container. <P>SOLUTION: The residual-liquid quantity detection device is equipped with a sensor room 33 having a liquid supply port 5 for introducing a liquid delivered from the liquid container 2 (2A) and for supplying the liquid to an external liquid consuming device, a diaphragm 48 which is movably held in the sensor room according to the liquid holding amount in the sensor room, a pressure-receiving plate 51 attached to the diaphragm, a recess 41 which communicates with the sensor room and is blockaded with the pressure-receiving plate when the liquid holding amount in the sensor room becomes a predetermined value or less, the piezoelectric element 44 for giving an oscillation to the recess and detecting the free oscillation state accompanying the oscillation given, a detector for detecting the amplitude value or frequency of the residual oscillatory waveform of a counter-electromotive force by the free oscillation state detected by the piezoelectric element and a calculation section for computing the residual liquid amount in the liquid container based on the amplitude value or frequency of the residual oscillation waveform detected by the detector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid remaining amount detecting device for a liquid container, and more particularly to a liquid remaining amount detecting device for a liquid container applied to a liquid ejecting apparatus such as an ink jet recording apparatus.

  Liquid ejecting heads for textile printing devices, microdispensers, and commercial recording devices that require ultra-high quality printing receive supply of liquid to be ejected from the liquid container, but operate without liquid supply If this occurs, the jet head is damaged due to so-called empty shots, and it is necessary to monitor the remaining amount of liquid in the container to prevent this.

For example, taking a recording apparatus as an example, various methods for detecting the remaining amount of ink in an ink cartridge, which is a liquid container, have been proposed, but when the remaining amount of liquid drops below a specified value, the flat plate is a spring. A technique for confirming a decrease in ink by moving away from the detection mechanism and stopping output of a detection signal from the detection mechanism is known (for example, Patent Document 1).
As another example, a piezoelectric sensor and a pressure receiving plate are attached so that the ink pack is sandwiched between flexible ink packs of a liquid storage container, a charge / discharge waveform signal is applied to the piezoelectric sensor, and the vibration amplitude at that time is determined. A device that detects the remaining amount of ink in the ink pack by detection is also proposed (Patent Document 2).

Japanese Patent Laid-Open No. 2004-306604 Japanese Patent Laid-Open No. 2004-136670

The detection mechanism disclosed in the above-mentioned Patent Document 1 can detect the time point when the ink is decreased by detecting the decrease of the ink by the separation of the flat plate, but the mechanical switch mechanism becomes complicated and the shape is reduced. Not only did it increase, but it was easy to cause failure, and it was difficult to determine whether it was due to ink exhaustion or sensor failure. Therefore, in order to grasp the decrease in ink more reliably by a simple means, it is desired to directly detect the ink itself.
In addition, it has been proposed to directly detect the presence or absence of ink in the sensor chamber by applying vibration to the sensor chamber in the detection mechanism and detecting the waveform of the residual vibration with a piezoelectric element. Since the amplitude of is extremely small, it is difficult to accurately distinguish the difference in the waveform of residual vibration depending on the presence or absence of liquid.

  In the structure in which the piezoelectric sensor means is directly attached to the ink pack of the liquid container disclosed in Patent Document 2, the deformation of the ink pack is not necessarily uniform due to the flexibility of the ink pack, and the output of the piezoelectric sensor is reduced due to a decrease in the remaining amount of ink. There is a drawback that it does not follow accurately.

  In order to solve the above problems, the present invention provides a diaphragm and a piezoelectric element in a liquid detection chamber connected to a liquid container, and accurately changes the volume of the liquid detection chamber by the diaphragm, and the vibration of the piezoelectric element associated therewith. It is an object of the present invention to provide an apparatus for detecting a remaining amount of liquid in a liquid container that detects an actual remaining amount of liquid and exhaustion of liquid from changes (amplitude and frequency) of waves.

The object of the present invention is achieved by the following (1) and (2).
(1) A sensor chamber having a liquid supply port for introducing the liquid delivered from the liquid storage unit and supplying the liquid to an external liquid consumption device is detected, and the remaining amount of liquid remaining in the sensor chamber is detected. A liquid remaining amount detection device for a liquid storage container,
A diaphragm housed in the sensor chamber so as to be movable in response to the amount of liquid contained in the sensor chamber;
A pressure receiving plate attached to the diaphragm;
A concave portion that communicates with the sensor chamber and is closed by the pressure receiving plate when the liquid storage amount of the sensor chamber is a predetermined amount or less;
A piezoelectric element that applies vibration to the recess and detects a free vibration state associated with the applied vibration;
A detection unit for detecting an amplitude value or a frequency of a residual vibration waveform of a counter electromotive force due to the free vibration state detected by the piezoelectric element;
Based on the amplitude value or frequency of the residual vibration waveform detected by the detection unit, a calculation unit that calculates the remaining amount of liquid in the liquid container,
A liquid remaining amount detecting device characterized by comprising:
(2) A sensor chamber having a liquid supply port for introducing the liquid delivered from the liquid storage section and supplying the liquid to an external liquid consumption device is detected, and the remaining liquid amount remaining in the sensor chamber is detected. A liquid remaining amount detection device for a liquid storage container,
A diaphragm housed in the sensor chamber so as to be movable in response to the amount of liquid contained in the sensor chamber;
A concave portion that communicates with the sensor chamber and is closed with the inner surface of the bottom of the sensor chamber when displaced with the diaphragm and the liquid storage amount of the sensor chamber becomes a predetermined amount or less;
A piezoelectric element that is attached to the diaphragm and detects a free vibration state associated with the applied vibration while applying vibration to the recess;
A detection unit for detecting an amplitude value or a frequency of a residual vibration waveform of a counter electromotive force due to the free vibration state detected by the piezoelectric element;
Based on the amplitude value or frequency of the residual vibration waveform detected by the detection unit, a calculation unit that calculates the remaining amount of liquid in the liquid container,
A liquid remaining amount detecting device characterized by comprising:
According to the configurations of (1) and (2) above, vibration is applied to the liquid by the piezoelectric vibration element to detect the amplitude or frequency of free vibration of the diaphragm, and the remaining liquid amount in the sensor chamber is determined from this amplitude or frequency. Since the calculation unit specifically calculates, it is possible to know the actual remaining amount until the ink runs out.

Further, it is desirable to have a pressure adjusting spring attached so that the diaphragm is displaced at a predetermined pressure.
As a result, the characteristic curve indicating the relationship between the distance from the support base of the piezoelectric vibration element to the pressure receiving plate (or from the support base of the piezoelectric vibration element to the inner surface of the bottom of the sensor chamber) and the amplitude of the residual vibration waveform can be Since the characteristic can be changed by changing the biasing force of the spring, a desired characteristic curve can be obtained.

The diaphragm is preferably a flexible film.
Thereby, the airtightness in a diaphragm can be improved, the penetration | invasion of the gas to the liquid in a sensor chamber can be prevented, and a high deaeration degree can be maintained.

Further, the diaphragm is preferably a thin plate material laminated with aluminum.
Thereby, airtightness can be improved more reliably, gas can be prevented from entering the liquid in the sensor chamber, and a high degree of deaeration can be maintained.

  In addition, since the liquid is ink, the liquid can be applied to a liquid ejecting apparatus such as an ink jet recording apparatus.

  According to the present invention, vibration is applied to the liquid by the piezoelectric vibration element to detect the amplitude or frequency of the free vibration of the diaphragm, and the liquid remaining amount in the sensor chamber is specifically calculated by the calculation unit from the amplitude or frequency. As a result, the actual remaining amount until the ink runs out can be known. In particular, in the present invention, the flexible diaphragm supports the piezoelectric vibration element or the pressure receiving plate cooperating with the piezoelectric vibration element, so that the volume change of the sensor chamber due to the decrease of the liquid can be accurately followed, and the vibration plate with a small number of parts. Can be amplified to a greater level, and the remaining amount or presence of liquid (ink) in the sensor chamber can be reliably detected.

Hereinafter, embodiments of a liquid remaining amount detection device according to the present invention and a liquid storage container including the same will be described with reference to the drawings. In the following embodiments, a sealed ink cartridge mounted on a recording apparatus will be described as an example of the liquid container.
FIG. 1 is a cross-sectional view showing an example of a liquid storage container provided with the liquid remaining amount detection device of the present invention. As shown in FIG. 1, an ink cartridge (liquid container) 1 is mounted on the recording apparatus, and includes a first case 10 and a second case 20 each having a bottomed box that forms a half-shell. Has a cartridge case. In the first case 10, an opening formed in the first case 10 is covered with a flexible film body 3 made of a resin film or the like so as to form a liquid storage portion 2 for storing a liquid such as ink. The case 10 is joined by thermal welding or the like.

  On the other hand, on the other side of the flexible film body 3, the periphery of the second case 20 is in pressure contact with the heat-welded portion of the flexible film body 3, and the second case 20 and the flexible film body The airtight space formed between the three is formed. This airtight space is a pressurized region 4 into which a pressurized fluid (pressurized air) is introduced from a pressurized fluid introduction port (not shown) from outside, and the pressurized fluid is introduced into this pressurized region 4, The flexible film body 3 is pressurized, and the liquid in the first case 10 is pressurized in the direction of discharging to the outside (direction of arrow A).

  A liquid supply port 5 connected to a liquid supply path of the recording apparatus is formed on the outer surface of the first case 10. The liquid supply port 5 has a packing 7 having an opening that elastically contacts the outer periphery of the liquid introduction needle 6 that is a liquid introduction member that is electrically connected to the recording head of the recording apparatus, and seals the opening of the packing 7 by contacting the end surface of the packing 7 A valve body 8 that stops and a spring 9 such as a coil spring that urges the valve body 8 toward the packing 7 are provided.

  In the liquid supply port 5, the valve 9 is normally kept closed by the spring 9 when not connected to the recording apparatus, and the valve body 8 is opened by the liquid introduction needle 6 while being connected to the recording apparatus. It is pressed in the valve direction and opened. Further, the liquid supply unit 5 and the liquid storage unit 2 are communicated with each other by a liquid inlet 11A and a liquid outlet 11B, and the remaining amount of liquid according to the present invention is detected in the middle of the liquid inlet 11A and the liquid outlet 11B. A device 30 is provided.

  In addition, as a configuration of the liquid storage portion 2, in addition to the case and the flexible film body as shown in FIG. 1, the peripheral portions of a flexible resin film such as an aluminum laminate film are bonded together. The ink pack formed by the above may be accommodated in a cartridge case, and FIG. 3 shows a cross-sectional view of an example thereof.

FIG. 2 is a cross-sectional view showing another example of a liquid container provided with the liquid remaining amount detection device of the present invention. A liquid storage container 1A shown in FIG. 2 includes an ink pack (liquid storage unit) that discharges ink stored by pressurization of the pressurization chamber 4A into a pressurization chamber 4A that is pressurized by a pressurizing unit (not shown). ) 2A. As a pressurizing method, pressurization is performed by feeding a pressurized fluid (pressurized air) from a pressurizing port 13 provided in a part of the wall surface of the pressurizing chamber 4A.
In addition, since the other structure is the same structure as the liquid container 1 shown in FIG. 1, it attaches | subjects the same code | symbol and abbreviate | omits detailed description.

  FIG. 3 is an enlarged cross-sectional view showing the structure of the remaining liquid level detection device 30A of the first embodiment of the remaining liquid level detection device 30 shown in FIG. 1 or FIG. In the state connected to the recording apparatus, an opening 31 communicating with the liquid inlet 11 </ b> A connected to the liquid container 2 (2 </ b> A) and an opening communicating with the liquid outlet 11 </ b> B connected to the liquid supply port 5 are formed in the bottom region. And a liquid detection chamber (sensor chamber) 33 whose upper portion is defined by a diaphragm 48.

  In this embodiment, the diaphragm 48 is formed of a flexible film-like member, has an opening in the center, and the outer peripheral portion is a liquid at a predetermined height position from the bottom of the sensor chamber on the inner peripheral wall of the sensor chamber 33. It is firmly fixed. Similarly, the outer periphery of the support base 45 of the piezoelectric vibration element 44 is fixed to the central opening of the diaphragm 48 in a liquid-tight state.

The piezoelectric vibration element 44 is fixed to the upper surface of the support base 45, the lower surface of the support base 45 is formed in parallel with the bottom inner surface 33A of the sensor chamber 33, and a pair of small holes 46 and 47 are provided in the sensor chamber 33. It is formed so as to penetrate from the chamber 33 so as to reach the vibration plate of the piezoelectric vibration element 44.
The small hole-shaped flow paths 46 and 47 communicate with a recess (cavity) 41 formed between the diaphragm of the piezoelectric vibration element 44 and the support base 45. With this configuration, the liquid in the sensor chamber 33 flows into the recess 41 through the flow paths 46 and 47, and thus the diaphragm of the piezoelectric vibration element 44 is in contact with the liquid in the recess 41.

  A pressure adjusting spring 50 (pressure adjusting means) in contact with the upper part of the diaphragm 48 is provided outside the sensor chamber 33, thereby stabilizing the diaphragm 48 from the outside of the sensor chamber 33 so that the sensor chamber 33 has a predetermined space. Is supporting.

  As the use of the ink consuming device connected to the liquid supply port 11B of the sensor chamber 33 progresses and the amount of liquid in the liquid container 2 and thus the amount of liquid in the sensor chamber 33 decreases, the liquid pressure in the sensor chamber 33 decreases. Then, the diaphragm 48 gradually deviates downward, and finally the lower surface of the support base 45 comes into contact with the bottom inner surface 33A of the sensor chamber 33. In this state, the small hole-like flow paths 46 and 47 of the support base 45 are closed by the bottom inner surface 33A of the sensor chamber 33, and therefore the recess 41 is in a sealed state.

  When a driving signal as shown in FIG. 5A is supplied to the piezoelectric vibration element 44 in a state where the pressure region 4 (pressure chamber 4A) of the liquid storage unit 2 (2A) is pressurized, the piezoelectric vibration element 44 is supplied. Is excited as an actuator for a predetermined time, and the diaphragm starts free vibration. A back electromotive force is generated in the piezoelectric vibration element 44 by the free vibration of the diaphragm, and this back electromotive force is output as an output signal of an output waveform. When the support base 45 is in contact with the bottom inner surface 33A and the concave portion 41 is closed, the liquid in the concave portion 41 hardly vibrates, and the output signal from the piezoelectric vibration element 44 is a linear signal without a fluctuation waveform. .

  FIG. 4 is an enlarged cross-sectional view showing the structure of the remaining liquid level detection device 30B of the second embodiment of the remaining liquid level detection device 30 shown in FIG. 1 or FIG. Also in the second embodiment, the liquid remaining amount detection device 30B is connected to the recording device, and the opening 31 communicates with the liquid inlet 11A connected to the liquid storage portion 2 (2A) at the bottom region. And a cylindrical liquid detection chamber (sensor chamber) 33 provided with an opening 32 communicating with the liquid outlet 11B connected to the liquid supply port 5.

  In this second embodiment, the diaphragm 48 is formed of a flexible film-like member, and its outer peripheral portion is fixed to the inner peripheral wall of the sensor chamber 33 in a liquid-tight state at a predetermined height position from the bottom of the sensor chamber. Has been. A pressure receiving plate 51 is fixed to the inside of the diaphragm 48 in a liquid-tight state.

  The support base 45 of the piezoelectric vibration element 44 is fixed in a liquid-tight state to the bottom inner surface 33A of the sensor chamber 33, and the piezoelectric vibration element 44 is provided on the lower surface thereof. The upper surface of the support base 45 is formed parallel to the lower surface of the pressure receiving plate 51, and a pair of small holes 46 and 47 are formed from the sensor chamber 33 to the piezoelectric vibration element 44 as in the first embodiment. It penetrates to the position of the diaphragm.

  Each of the small hole-shaped flow paths 46 and 47 communicates with a recess 41 (cavity) formed between the diaphragm of the piezoelectric vibration element 44 and the support base 45. With this configuration, the liquid in the sensor chamber 33 flows into the recess 41 through the small holes 46 and 47, and the diaphragm of the piezoelectric vibration element 44 is in contact with the liquid in the recess 41.

  A pressure adjusting spring 50 (pressure adjusting means) in contact with the upper part of the diaphragm 48 is provided outside the sensor chamber 33, thereby stabilizing the diaphragm 48 from the outside of the sensor chamber 33 so that the sensor chamber 33 has a predetermined space. Is supporting.

  When the operation of an ink consuming device (recording device or the like) connected to the liquid supply port 5 of the sensor chamber 33 progresses and the amount of liquid in the liquid storage unit 2 (2A) decreases, the pressure in the sensor chamber 33 as shown in FIG. As a result, the diaphragm 48 gradually deviates downward, and finally the lower surface of the pressure receiving plate 51 comes into contact with the upper surface of the support base 45 of the piezoelectric vibration element 44 in the sensor chamber 33. In this state, the small hole-shaped flow paths 46 and 47 of the support base 45 are closed by the pressure receiving plate 51, and therefore the concave portion 41 of the diaphragm is in a sealed state.

  When a driving signal as described in the first embodiment is supplied to the piezoelectric vibration element in a state where the pressurization region 4 (pressurization chamber 4A) of the liquid storage unit 2 (2A) is pressurized, the piezoelectric vibration element 44 is supplied. Is excited as an actuator for a predetermined time, and the diaphragm starts free vibration (residual vibration). A back electromotive force is generated in the piezoelectric vibration element 44 by the free vibration of the diaphragm, and this back electromotive force is output as an output signal of an output waveform.

  Here, the state of vibration by the diaphragm will be further described. The diaphragm of the piezoelectric vibration element 44 is formed on the diaphragm by the liquid in the sensor chamber 33 passing through the small hole-like channels 46 and 47 of the diaphragm support base 45. With this liquid, the diaphragm freely vibrates with a relatively large amplitude as shown in FIG. Further, since the pressure receiving plate 51 facing the piezoelectric vibration element 44 is supported on the inner peripheral wall of the sensor chamber 33 by a flexible diaphragm 48, free vibration caused by the vibration plate is amplified. As a result, the back electromotive force in the piezoelectric vibration element 44 is amplified.

  As described above, when the consumption of ink in the recording apparatus progresses and the ink (liquid) in the liquid container 2 (2A) decreases and becomes less than a predetermined amount, the pressure receiving plate 51 supported by the diaphragm 48 is also liquid. Follow the decrease and move downward. There is a certain correlation between the distance L from the support base 45 of the piezoelectric vibration element 44 to the pressure receiving plate 51 and the amplitude or frequency of vibration of the vibration plate.

Here, the amplitude of the diaphragm will be examined. FIG. 7 is a graph showing the relationship between the distance L between the support base 45 and the pressure receiving plate 51 in the sensor chamber 33 of the liquid remaining amount detection device 30B of the second embodiment and the amplitude of the residual vibration waveform. In the region F where the distance L in the sensor chamber 33 is filled with the liquid container 2 (2A) and the distance L is large, the residual vibration waveform of the free vibration of the diaphragm has a relatively large amplitude. Further, when the height in the sensor chamber 33, that is, the value of the distance L is decreased, the amplitude of the residual vibration waveform is decreased. The distance L is the distance from the support base 45 of the piezoelectric vibration element 44 to the bottom inner surface 33A of the sensor chamber 33 in the liquid remaining amount detection device 30A according to the first embodiment.
The characteristic curve between the distance L and the amplitude of the residual vibration waveform shown in FIG. 7 can be changed by changing the urging force of the pressure adjusting spring 50. Therefore, a desired characteristic curve can be obtained.

  In a state where the remaining amount of ink in the liquid storage unit 2 (2A) is low, the height (distance L) in the sensor chamber 33 and the volume of the liquid storage unit 2 (2A), that is, the remaining amount of ink in the storage unit There is a certain correlation between them, and the amplitude of the residual vibration waveform of the back electromotive force due to the free vibration state detected by the piezoelectric element is detected by the detection unit provided in the liquid remaining amount detection device 30 (30A, 30B). The amount of residual ink in the liquid storage unit 2 (2A) can be calculated from the amplitude of the residual vibration waveform detected by the detection unit by the calculation unit provided in the remaining liquid amount detection device 30 (30A, 30B). FIG. 8 is a graph showing the relationship between the remaining amount of ink in the liquid storage unit 2 (2A) obtained by this calculation unit and the amplitude of the residual vibration waveform.

  If the liquid storage container 1 (1A) and the recording apparatus are configured to be electrically connectable, the detection unit and / or the calculation unit are provided in the liquid storage container 1 (1A). It may be provided in the recording apparatus. When the calculation unit is provided in the recording apparatus, different calculation parameters (parameters for the correspondence relationship between the distance L and the remaining ink amount) are calculated for each type of liquid storage container 1 (1A) having a different liquid storage amount. It may be provided for.

  As is clear from the graph of FIG. 8, when the remaining amount of ink in the liquid container 2 (2A) decreases, the amplitude of the residual vibration waveform suddenly decreases from a certain point in time. It can be determined whether the remaining amount is in the liquid container 2 (2A), and after the pressure receiving plate 51 held by the diaphragm 48 comes into contact with the upper surface of the support base 45 of the piezoelectric vibration element 44, the vibration plate is free. The vibration causes the ink in the concave portion 41 communicating with the small hole-like flow paths 46 and 47 of the support base 45 to hardly vibrate and has a very small amplitude, so that the ink exhaustion of the liquid storage portion 2 (2A) is found. .

  Each of the above embodiments is an example of detecting the remaining amount of ink in the liquid storage unit from the amplitude of the residual vibration waveform by the piezoelectric vibration element. However, not only the amplitude but also the frequency of the residual vibration is detected in the liquid storage unit. It is possible to know the remaining ink amount or ink exhaustion.

As described above, in the present invention, the detection unit that detects the amplitude of the residual vibration waveform due to the free vibration of the diaphragm of the piezoelectric vibration element, and the amplitude in the residual vibration waveform detected by the detection unit Since it has a calculation unit that calculates the remaining amount of liquid, the ink in the liquid storage unit, in other words, how much ink is remaining in the ink storage container of the recording device, and the ink is exhausted and the ink runs out. Can be identified.
In the present invention, the remaining amount of liquid is not detected by attaching a piezoelectric sensor or a pressure receiving plate to the ink pack of the liquid container, but a piezoelectric vibration element is provided in a sensor chamber defined by a diaphragm. Because changes in the vibration waveform (amplitude, frequency) are detected in the chamber, the displacement of the sensor chamber is accurate, it is possible to accurately detect the remaining amount of liquid, and with a small number of parts, the level of free vibration of the diaphragm is large. Can be reliably detected.

It is sectional drawing which shows an example of the liquid storage container provided with the liquid residual amount detection apparatus of this invention. It is sectional drawing which shows another example of the liquid storage container provided with the liquid residual amount detection apparatus of this invention. It is an expanded sectional view which shows the structure of the liquid residual amount detection apparatus in the 1st Embodiment of this invention. It is an expanded sectional view which shows the structure of the liquid residual amount detection apparatus in the 2nd Embodiment of this invention. It is a figure which shows the drive signal applied to a piezoelectric vibration element, and the output signal of a piezoelectric vibration element in the state with sufficient liquid of a liquid storage part. It is a figure which shows the relationship between the ink residual amount of a liquid accommodating part, and the pressure in a sensor chamber. It is a figure which shows the relationship between the height of the sensor chamber which concerns on this invention, and the amplitude of the residual vibration waveform by a piezoelectric vibration element. It is a figure which shows the relationship between the ink residual amount of a liquid accommodating part, and the amplitude of the residual vibration waveform by a piezoelectric vibration element.

Explanation of symbols

1, 1A cartridge (liquid container)
2, 2A Liquid storage unit 3 Flexible film body 4 Pressurization region 4A Pressurization chamber 5 Liquid supply port 30, 30A, 30B Liquid detection device 33 Sensor chamber 44 Piezoelectric vibration element 45 Support base 46, 47 Channel 48 Diaphragm 50 Pressure adjusting spring 51 Pressure receiving plate

Claims (6)

Liquid storage for introducing a liquid delivered from a liquid storage section and having a sensor chamber having a liquid supply port for supplying the liquid to an external liquid consuming device, and detecting a remaining amount of liquid remaining in the sensor chamber A device for detecting a remaining amount of liquid in a container,
A diaphragm housed in the sensor chamber so as to be movable in response to the amount of liquid contained in the sensor chamber;
A pressure receiving plate attached to the diaphragm;
A concave portion that communicates with the sensor chamber and is closed by the pressure receiving plate when the liquid storage amount of the sensor chamber is a predetermined amount or less;
A piezoelectric element that applies vibration to the recess and detects a free vibration state associated with the applied vibration;
A detection unit for detecting an amplitude value or a frequency of a residual vibration waveform of a counter electromotive force due to the free vibration state detected by the piezoelectric element;
Based on the amplitude value or frequency of the residual vibration waveform detected by the detection unit, a calculation unit that calculates the remaining amount of liquid in the liquid container,
A liquid remaining amount detecting device characterized by comprising: Liquid storage for introducing a liquid delivered from a liquid storage section and having a sensor chamber having a liquid supply port for supplying the liquid to an external liquid consuming device, and detecting a remaining amount of liquid remaining in the sensor chamber A device for detecting a remaining amount of liquid in a container,
A diaphragm housed in the sensor chamber so as to be movable in response to the amount of liquid contained in the sensor chamber;
A concave portion that communicates with the sensor chamber and is closed with the inner surface of the bottom of the sensor chamber when displaced with the diaphragm and the liquid storage amount of the sensor chamber becomes a predetermined amount or less;
A piezoelectric element that is attached to the diaphragm and detects a free vibration state associated with the applied vibration while applying vibration to the recess;
A detection unit for detecting an amplitude value or a frequency of a residual vibration waveform of a counter electromotive force due to the free vibration state detected by the piezoelectric element;
Based on the amplitude value or frequency of the residual vibration waveform detected by the detection unit, a calculation unit that calculates the remaining amount of liquid in the liquid container,
A liquid remaining amount detecting device characterized by comprising:   3. The liquid remaining amount detecting device according to claim 1, further comprising pressure adjusting means attached so that the diaphragm is displaced at a predetermined pressure.   The liquid remaining amount detection device according to claim 1, wherein the diaphragm is a flexible film.   The liquid remaining amount detection device according to claim 1, wherein the diaphragm is a thin plate material laminated with aluminum.   The liquid remaining amount detection apparatus according to claim 1, wherein the liquid is ink.

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