JP2009119853A - Liquid storing container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid storing container capable of detecting the remaining amount of liquid or detecting a pressurized state/a non-pressurized state even if a pressing system for introducing a pressurized fluid into a region where the liquid is stored is adopted. <P>SOLUTION: The liquid storing container has an ink storing part 107 which discharges ink 100 by introducing a pressurized fluid (for example, air) 101 into a region where the ink 100 is stored, an ink outlet opening 127 for feeding the liquid from the ink storing part 107 to a printer 11, and ink detecting units 1 and 111. The ink detecting units 1 and 111 comprise ink storing parts 4 and 200, a sensor chip 7 and a piezoelectric element 132C applying vibration to sensor cavities 7a and 132A communicating with the ink storing parts 4 and 200 and receiving the liquid and detecting the state of free vibration accompanied by the vibration, and moving members 5 and 300 displaced in accordance with pressurized states in the ink storing parts 4 and 200 at positions opposing the sensor cavities 7a and 132A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid container suitable for ink remaining amount detection or pressure / non-pressure detection in an ink cartridge.

  An ink cartridge having an ink remaining amount detection function is disclosed in Patent Document 1. In this ink remaining amount detection principle, a moving member that moves in response to the liquid level is provided in the ink storage unit, and a piezoelectric element is formed in a recess (sensor cavity) that can form a closed space in cooperation with the wall surface of the moving member. By applying vibration, the state of free vibration accompanying the vibration is detected.

  In Patent Document 1, a deformable ink pack is provided in the casing of the ink cartridge and upstream of the ink storage unit. Then, a pressurized fluid such as air is introduced around the ink pack disposed in the casing of the ink cartridge, and the ink is pressurized from the outside by the air to discharge the ink in the ink pack. Therefore, when the ink remaining amount in the ink pack decreases, the ink pressure supplied from the ink pack to the liquid storage unit also decreases.

  For detecting the remaining amount of ink, a moving member that is displaced according to the fluid pressure in the ink storage unit is provided, and the output from the piezoelectric element when the fluid pressure from the ink pack decreases and the sensor cavity is closed by the moving member is used. On the basis of this, an ink end detection has been proposed.

  On the other hand, as an ink supply method of the ink cartridge, an air supply system that supplies air directly into the ink storage unit may be considered. Although there is a need to incorporate an ink detection device for this type of ink cartridge, when the ink storage unit of this method is combined with the ink remaining amount detection function of Patent Document 1, even if the ink in the ink storage unit runs out, As long as air pressurization continues, air pressure continues to act on the ink storage part of the ink detection device instead of the ink pressure, so the moving member in the ink storage part does not move, so depending on the position of the moving member Therefore, the detection principle of detecting ink end cannot be adopted as it is.

  As another pressurization method, there is an ink cartridge that is used as a sub tank and is used in combination with a large capacity main tank connected to the sub tank. In this case, ink is pressurized and supplied from the ink cartridge as the sub tank by the ink pressure supplied from the main tank. Even in the ink cartridge as the sub tank, it is necessary to detect the pressurization / non-pressurization of the ink as described above.

JP 2006-160371 A

  Therefore, an object of the present invention is to detect the remaining amount of liquid or to pressurize / not pressurize the liquid storage area even if a pressurized system in which a pressurized fluid is introduced into the liquid storage area is employed. An object of the present invention is to provide a liquid container that can detect the above.

  One embodiment of the present invention is a liquid container that discharges the liquid by introducing a pressurized fluid into a region in which the liquid is stored, and a liquid that supplies the liquid from the liquid container to a liquid consuming device. An outlet, and a detection device provided between the liquid container and the liquid outlet, wherein the detection device is a liquid storage device provided between the liquid container and the liquid outlet. A piezoelectric element that is in a state of free vibration accompanying the vibration by applying vibration to a sensor cavity that communicates with the liquid storage section and receives the liquid, and a position facing the sensor cavity. And a moving member that is displaced in response to a pressurized state in the storage unit.

  In one embodiment of the present invention, the liquid from the liquid storage portion is pressurized and discharged by introducing a pressurized fluid into the region of the liquid storage portion in which the liquid is stored. For this reason, after all the liquid in the liquid storage part is discharged to the liquid storage part, the pressurized fluid itself is introduced from the liquid storage part to the liquid storage part. This point is different from Patent Document 1. In addition, when the liquid is introduced from the liquid storage unit, the moving member disposed in the liquid storage unit is pressurized by the liquid pressure. When the pressurized fluid is introduced from the liquid storage unit, the pressurized fluid pressure is But each works. Therefore, the moving member is set at a position away from the sensor cavity as long as the liquid container is pressurized, and is hardly displaced even when the acting pressure is changed from the hydraulic pressure to the fluid pressure. This point is also different from Patent Document 1. However, when the liquid container is not pressurized, the moving member is displaced to the position on the sensor cavity side, unlike the position described above.

  In one aspect of the present invention, vibration is applied to a sensor cavity that communicates with a liquid storage portion and receives liquid, and pressure is applied regardless of the position of the moving member by a piezoelectric element that is in a free vibration state associated with the vibration. The presence or absence of the remaining amount of liquid can be detected based on the difference in the medium, or the pressurized / non-pressurized state can be detected based on the position of the moving member.

  As an example, a case where the pressurized fluid is different from the liquid to be inspected will be described. In this case, the piezoelectric element outputs different signals depending on whether the medium in the region between the sensor cavity and the moving member is the liquid or the liquid when the liquid container is pressurized. can do. The different signal is the frequency of free vibration or the amplitude of free vibration. In addition, at the time of non-pressurization when the liquid is stored, one surface of the moving member can make the sensor cavity a closed space. In this case, the piezoelectric element can output different signals depending on whether the liquid container is pressurized or not. This different signal is the amplitude of the free vibration. Alternatively, it is also possible to detect when the liquid container is pressurized and non-pressurized based on a combination of the frequency and amplitude values of the free vibration output from the piezoelectric element.

  Thus, when the pressurized fluid is different from the liquid to be inspected, the remaining amount of liquid can be detected by the difference in the medium acting on the moving member, and the pressurized / non-pressurized state can be detected based on the displacement of the moving member. . A representative example of the pressurized fluid in this case is air.

  As another example, in one embodiment of the present invention, there is application even when the pressurized fluid is the same as the liquid to be inspected. In this example, for example, an ink cartridge is used as a sub tank and is used in combination with a large capacity main tank connected to the sub tank. In this case, ink is pressurized and supplied from the ink cartridge as the sub tank by the ink pressure supplied from the main tank.

  Also in this case, at the time of non-pressurization when the liquid is accommodated, one surface of the moving member makes the sensor cavity a closed space, and the piezoelectric element is different between when the liquid container is pressurized and when it is not pressurized. A signal can be output. Therefore, for example, it is possible to detect the pressurized / non-pressurized state of the liquid storage portion of the ink cartridge used as the sub tank. This different signal is the amplitude of the free vibration. Alternatively, it is possible to detect when the liquid container is pressurized and when it is not pressurized based on a combination of the values of the frequency and amplitude of the free vibration output from the piezoelectric element.

  In one aspect of the present invention, the liquid storage part is configured by sealing an opening formed on an upper surface with a film that can be deformed according to a pressurized state, and the piezoelectric element is placed on the bottom of the liquid storage part. Can be arranged.

  In this way, the liquid storage part can be deformed by a film that responds to the pressure of the liquid or pressurized fluid in the liquid storage part, and can be easily formed in a liquid-tight space by the film, and has a simple structure compared to a mechanical seal. Liquid leakage and liquid evaporation can be prevented.

  In one aspect of the present invention, the moving member can be moved by deformation of the film corresponding to a change in the pressurized state of the liquid storage unit, and preferably the moving member can be fixed to the film.

  Thus, since the moving member is displaced by pressurization / non-pressurization, the output waveform of the piezoelectric element changes to detect the pressurization / non-pressurization state.

  In one aspect of the present invention, the moving member can be biased by a biasing member in a direction in which the piezoelectric element is disposed.

  By adjusting the urging force of the urging member, it is possible to adjust the timing and amount of displacement of the moving member in response to the change in the applied pressure, thereby reliably detecting the pressurized / non-pressurized state.

  Next, an embodiment of the present invention will be described. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not always.

(Principle of the present invention)
As a condition for the present invention to be established, it is necessary that two or more of the following three states can be distinguished as the output of the piezoelectric element.

  1A to 1C schematically show three states that can be taken by the main part of the ink detection unit 1 as a detection device. In each of FIGS. 1A to 1C, the opening 2a at the top of the resin-made ink detection unit case 2 is sealed with a film 3 as a diaphragm. The ink detection unit case 2 closed by the film 3 is an ink storage unit 4 as a liquid storage unit. The moving member 5 is fixed to the film 3 and is displaced together with the film 3 according to the pressure in the ink storage unit 4. A sensor base 6 made of SUS or the like is provided in the opening 2 b at the bottom of the ink detection unit case 2, and a sensor chip 7 as a piezoelectric element including a piezoelectric element is disposed on the lower surface of the sensor base 6. The sensor base 6 is formed with two holes 6 a and 6 b communicating with the ink storage unit 4. The sensor chip 7 is formed with a sensor cavity 7a communicating with the two holes 6a and 6b. As shown in black in FIGS. 1A to 1C, the two holes 6a and 6b and the sensor cavity 7a are preliminarily filled with ink 100 as a liquid. 1A and 1B, the ink 100 exists in the ink storage unit 4, and in FIG. 1C, the ink storage unit 4 has a pressurized fluid (for example, air) other than the ink from the ink 100. ) 101.

  The ink storage unit 4 shown in FIGS. 1A to 1C communicates with an upstream ink storage unit (not shown) and an downstream ink outlet (not shown). Ink pressurized in the upstream ink storage unit is filled in the ink storage unit 4 and supplied to an ink consuming device such as a printer through the ink storage unit 4 via the ink outlet.

  FIG. 1A shows a state A in which the moving member 5 is in contact with the sensor base 6 and the sensor cavity 7a is closed in the closed space. 1B and 1C, the moving member 5 is located above the sensor base 6, and the sensor cavity 7a is an open space. FIG. 1A shows a state where the upstream ink containing portion is not pressurized. In a state where pressure is not applied, the moving member 5 is lowered and is in contact with the sensor base 6. This state A can be realized by the weight of the moving member 5, but the moving member 5 may be urged toward the sensor base 6 by an urging member (not shown). In any case, the sensor cavity 7a is closed by the moving member 5 if the hydraulic pressure in the ink storage unit 4 does not act.

  State A in FIG. 1A indicates an ink end state when an ink pack that is deformed by external pressurization and discharges ink is used as an ink container as in Patent Document 1. However, this is not the case with the present invention. That is, when all the ink in the ink pack is consumed as in Patent Document 1, the volume of the ink pack becomes substantially zero, and no pressure acts on the ink storage unit. As a result, the volume in the ink storage unit 4 is reduced, the film 3 is deformed, the moving member 5 is lowered together with the film 3, and the sensor cavity 7a is closed.

  However, in the present invention, an ink pack is not used, and instead, a pressurized fluid is introduced into the inside of the ink container and the ink is pumped. Accordingly, even if the ink in the ink storage portion is exhausted, the pressurized fluid is introduced into the ink storage portion 4, that is, the ink is introduced as the fluid is introduced into the ink storage portion and the inside of the ink storage portion is pressurized. Since the fluid is discharged to the storage unit, the state A of FIG. In the case of the present invention, the state A shown in FIG. 1A can be in the non-pressurized state where the inside of the ink containing portion is not pressurized.

  A state B in FIG. 1B shows a state of “ink present” in which ink is being pumped from the ink containing portion on the upstream side of the ink containing portion. In this state B, the film 3 is expanded by the pressure of the ink, the moving member 5 is displaced upward together with the film 3, and the sensor cavity 7 a is an open space communicating with the ink storage unit 4.

  A state C in FIG. 1C shows an “ink end” state in which a pressurized fluid (for example, air) 101 is being pumped from the upstream ink storage portion where ink has run out. In this state C, the film 3 is expanded by the pressure of a pressurized fluid (for example, air) 101 different from the ink, the moving member 5 is displaced upward together with the film 3, and the sensor cavity 7 a communicates with the ink storage unit 4. It is an open space.

  1B and FIG. 1C have almost no difference in the position of the moving member 5. The difference is that the medium between the moving member 5 and the sensor base 6 is ink (see FIG. 1B). Or the pressurized fluid (in the case of FIG. 1C).

  2A to 2C schematically show output waveforms of the piezoelectric elements in the sensor chip 7 in the states of FIGS. 1A to 1C obtained by experiments by the inventor. Is shown.

  The characteristics of the output waveforms in FIGS. 2A to 2C are as shown in the following table.

State Frequency Amplitude State A A1 kHz AH (mV; almost 0 mV)
State B B1 (<A1) kHz BH (> AH) (mV)
State C C1 (≈A1) kHz CH (AH <CH <BH) (mV)
The characteristics shown in the above table are examples. For example, when a moving member with a flow path according to an embodiment described later is used, the frequency A1 <the frequency B1 is reversed, or the amplitudes AH, BH, and CH are applied to the piezoelectric element. The states A to C can be discriminated by at least the amplitude of free vibration (AH <CH <BH in the data in the above table), although it may be reversed by changing the frequency of the excitation waveform. Or it is also possible to discriminate | determine states AC by the combination of an amplitude and a frequency. That is, even if the frequencies A1 and C1 cannot be distinguished from the data in the above table, it is possible to determine whether the state is the state A or the state C by comparing the amplitudes AH and CH.

(Description of liquid container)
3 and 4 schematically show two examples of the liquid container. As a configuration common to FIGS. 3 and 4, an ink containing portion 107 is provided in the case main body 105 as a sub tank of the ink cartridge. One end opening portion of the ink containing portion 107 is sealed with a film 115, the ink containing portion 107 is liquid-tight, and evaporation of the stored ink is prevented. One end opening of the case body 105 is closed by a lid 121. The ink container 107 is provided with an ink outlet 127 as a liquid outlet. An ink detection unit 111 as a detection device is disposed between the ink outlet 127 and the ink storage unit 107.

  In the example of FIG. 3, a pressurized fluid introduction port 128 (in this embodiment, the pressurized fluid is pressurized air) communicating with the ink storage unit 107 is provided, and the ink flows back to the path reaching the pressurized fluid introduction port 128. A check valve 128A is arranged to prevent this.

  In the example of FIG. 3, the pressurized fluid (for example, air) 101 increases as the remaining amount of the ink 100 in the ink container 107 decreases, and when the ink 100 runs out, the pressurized fluid (for example, air) Air) 101 only. Therefore, as long as there is ink in the ink container 107, the ink 100 is pumped to the ink detection unit 111 by pressurized air. When the ink 100 runs out, the pressurized air is pumped. In the example of FIG. 3, the introduction of pressurized fluid means that the internal pressure in the ink containing portion 107 increases due to the introduction of air from the pressurized air introduction port to the ink containing portion 107, and the ink from the ink containing portion 107 Ink or air flows toward the outlet 127, and the internal pressure in the ink storage portion increases accordingly. Further, the time when the ink container is pressurized indicates this state.

  Therefore, in the ink cartridge of FIG. 3, in a non-pressurized state where pressurized air is not supplied to the pressurized fluid introduction port 128, the ink detection unit 111 is in the state A of FIG. Based on the output signal, the “non-pressurized state” is detected. In a pressurized state in which pressurized air is supplied to the pressurized fluid introduction port 128, as long as there is ink in the ink containing portion 107, the ink detection unit 111 changes to the state B of FIG. Based on the output signal of B), the “pressurized state” and the “ink present state” are detected. When the pressurized air is supplied to the pressurized fluid introduction port 128 and ink is exhausted in the ink container 107, the ink detection unit 111 changes to the state C of FIG. Based on the output signal of (C), “pressurized state” and “ink end state” are detected.

  In the example of FIG. 4, an ink introduction port 129 is provided instead of the pressurized fluid introduction port 128 of FIG. 3. That is, the ink cartridge having the case main body 105 is used as a sub tank, and the main tank 130 is connected to the ink introduction port 129 of the sub tank. Pressurized fluid (for example, air) 101 is pressurized and supplied to the inside of the main tank 130 by the pressurizing pump 131, and the ink 100 inside is supplied to the ink containing unit 107 through the ink inlet 129 of the sub tank by the pressurized air. The Therefore, the pressurized fluid in this case is different from the example of FIG. 3 in that it is ink from the main tank. In the example of FIG. 4, the introduction of pressurized fluid means that the internal pressure in the ink containing portion 107 increases due to the introduction of ink or air from the ink introduction port 129 to the ink containing portion 107, and the pressure from the ink containing portion 107 is increased. Ink or air flows toward the ink outlet 127, and the internal pressure in the ink storage portion increases accordingly. Further, the time when the ink container is pressurized indicates this state.

  In the example of FIG. 4, since the detection of the ink remaining amount in the sub tank is not emphasized, the pressure state or the non-pressure state is detected. That is, the non-pressurized state A of FIG. 1A is detected based on the output signal of FIG. 2A, and the pressurized state B of FIG. 1B is the output of FIG. It is detected based on the signal. In the ink end state where no ink exists in both the main tank 130 and the case main body 105 as the sub tank in FIG. 4, the pressurized air in the main tank 130 is introduced into the ink detection unit 111. Therefore, this ink end state is the same as the state C in FIG. 1C, and the ink end can be detected based on the output signal in FIG.

(Outline of liquid consuming equipment)
As shown in FIG. 5, the printer 11 as the liquid consuming device or the liquid consuming device of the present embodiment is covered with a frame 12. In the frame 12, as shown in FIG. 6, a guide shaft 14, a carriage 15, a recording head 20 as a liquid ejecting head, a valve unit 21, an ink cartridge 23 (see FIG. 5) as a liquid container, and pressurization. A pump 25 (see FIG. 5) is provided.

  As shown in FIG. 5, the frame 12 is a substantially rectangular parallelepiped box, and a cartridge holder 12a is formed on the front surface thereof.

  As shown in FIG. 6, the guide shaft 14 is formed in a rod shape and is installed in the frame 12. In the present embodiment, the direction in which the guide shaft 14 is installed is referred to as a main scanning direction. The carriage 15 is inserted so as to be relatively movable with respect to the guide shaft 14, and can be reciprocated in the main scanning direction. The carriage 15 is connected to a carriage motor (not shown) via a timing belt (not shown). The carriage motor is supported by the frame 12, and when the carriage motor is driven, the carriage 15 is driven via the timing belt, and the carriage 15 is reciprocated along the guide shaft 14, that is, in the main scanning direction. The

  The recording head 20 provided on the lower surface of the carriage 15 is provided with a plurality of nozzles (not shown) for ejecting ink as a liquid, and ejects ink droplets onto a printing medium such as recording paper. Records print data such as characters. The valve unit 21 is mounted on the carriage 15 and supplies the temporarily stored ink to the recording head 20 with the pressure adjusted.

  In the present embodiment, the valve unit 21 can individually supply two types of ink to the recording head 20 with the pressure adjusted. In the present embodiment, a total of three valve units 21 are provided and correspond to six ink colors (black, yellow, magenta, cyan, light magenta, and light cyan).

  A platen (not shown) is provided below the recording head 20, and this platen is used as a target to be fed in a sub-scanning direction orthogonal to the main scanning direction by a paper feeding means (not shown). It is for supporting the recording medium.

  An ink cartridge 23 shown in FIG. 5 is detachably mounted on a cartridge mounting portion of the ink jet recording apparatus, and supplies ink to a recording head (liquid ejecting head) mounted on the recording apparatus. 3 or 4 is used as the ink cartridge 23. In the type shown in FIG. 3, the pressurizing pump 25 shown in FIG. 5 is connected to the pressurized fluid introduction port 128 shown in FIG. Instead of using the pressurizing pump shown in FIG. 5, an external pressurizing pump is used.

(Specific example of ink detection unit)
As shown in FIGS. 7, 8 (A), and 8 (B), the ink detection unit 111 of the present embodiment capable of detecting the three states of FIGS. 1 (A) to 1 (C), for example, A resin-made ink detection unit case 133 attached to the case main body 105 of the ink cartridge by a rotation operation, and a piezoelectric element fixed to the back side of the ink detection unit case 133 via a sensor base 141 as a detection unit installation member Sensor chip 132 (corresponding to sensor chip 7 in FIGS. 1A to 1C) and an insulating sensor sealing film 142 covering the surface of sensor base 141 around sensor chip 132, and the like. I have.

  The ink detection unit case 133 includes an ink outlet member 109 into which an ink supply needle (liquid outlet needle) on the cartridge mounting portion side is inserted and connected. The ink outlet member 109 corresponds to the ink outlet 127 of FIGS. The ink detection unit case 133 includes an ink detection unit case main body 133 a having an ink storage unit 200 as a liquid storage unit communicating with the ink lead-out member 109. The ink storage unit 200 corresponds to the ink storage unit 4 shown in FIGS. 1A to 1C. The ink storage unit 200 includes a moving member 300 shown in FIG. 7 (FIGS. 1A to 1). (Corresponding to the moving member 5 of (C)) is provided to be displaceable. Further, a sealing film 156 (diaphragm, which is a diaphragm, which defines a pressure chamber for detecting the remaining amount by sealing the open surface of the ink storage unit 200, is shown in FIGS. 1 (A) to 1 (C). Equivalent to the film 3) and a pressing member 133 b that presses (biases) the moving member 300 via the sealing film 156.

  The pressing member 133b is configured such that an engagement shaft 152 protruding from the outer periphery of the ink detection unit case main body 133a is fitted into a hole 151a of a locking piece 151 protruding from the base end side, whereby the ink detection unit case The ink detection unit case main body 133a is connected to the ink detection unit case main body 133a via the sealing film 156 by connecting the main body 133a to the main body 133a so as to be rotatable and further connecting the front end side to the ink detection unit case main body 133a by a spring 153 as an urging member. The member 300 is fixed so as to press (bias) the member 300.

  A flow path opening / closing mechanism 155 that opens the flow path when the ink supply needle on the cartridge mounting portion side is inserted is mounted on the ink lead-out member 109. The flow path opening / closing mechanism 155 includes a cylindrical seal member 155a fixed to the ink outlet member 109, a valve body 155b that holds the flow path closed by sitting on the seal member 155a, and a valve body 155b. And a spring member 155c that urges the seal member 155a in the seating direction.

  The opening end of the ink outlet member 109 to which the flow path opening / closing mechanism 155 is attached is sealed with a sealing film 157 (see FIG. 7). The sealing film 157 is welded to the opening end face of the ink lead-out member 109 and the end face of the seal member 155a attached to the ink lead-out member 109.

  When the ink cartridge 23 (see FIG. 5) is mounted on the cartridge mounting portion of the recording apparatus, the ink supply needle mounted on the cartridge mounting portion breaks through the sealing film 157 and is inserted into the ink lead-out member 109. At this time, the ink supply needle inserted into the ink lead-out member 109 causes the valve body 155b to separate from the seal member 155a, so that the flow path in the ink detection unit case 133 is in communication with the ink supply needle, and the recording apparatus Ink supply to the side becomes possible.

  Further, as shown in FIG. 8B, the ink detection unit case main body 133a has a container fitting portion 135 that is rotatably fitted to the attachment portion of the case main body 105 on the back side thereof. Inside the container fitting portion 135, a connecting needle 111a that is inserted and connected to an ink lead-out member (not shown) of the ink storage portion 107 of FIG. 3 or FIG. 4 is provided. The connection needle 111a is inserted into the ink lead-out member of the ink storage unit 107 through the sealing film. As a result, the valve mechanism in the ink lead-out member is opened and ink can be led out.

  The sensor chip 132 is a piezoelectric detection means fixed to the back side of the ink detection unit case main body 133a so that vibration can be applied to a sensor cavity 132A as a detection space described later with reference to FIGS. The change in free vibration (residual vibration) accompanying the change in (pressure) is output as an electrical signal. By analyzing the output signal of the sensor chip 132 by the control circuit on the recording apparatus side, the remaining amount of ink in the ink containing portion 107 of FIG. 3 or FIG. 4 is detected.

(Detection unit)
FIG. 9 is a perspective view of the sensor base 141 (corresponding to the sensor base 6 in FIGS. 1A to 1C) viewed from below. As shown in FIG. 9, the sensor base 141 is provided with a first through hole 141A as a supply path penetrating in the thickness direction and a second through hole 141B as a discharge path. The sensor base 141 is made of, for example, SUS.

  FIG. 10 is a perspective view of the sensor base 141 on which the sensor chip 132 is mounted as viewed from above. In FIG. 10, a sensor chip 132 is a sensor cavity 132A as a detection space for receiving ink (liquid) to be detected (in FIG. 10, it is under a diaphragm 132B and a piezoelectric element 132C, and FIGS. C) corresponds to the sensor cavity 7a), and the sensor cavity 132A communicates with the first through-hole 141A and the second through-hole 141B of the sensor base 141. The upper surface of the sensor cavity 132A is closed with a diaphragm 132B. Further, a piezoelectric element 132C is disposed on the upper surface of the diaphragm 132B.

  For example, the piezoelectric element 132C applies vibration to the sensor cavity 132A and outputs a residual vibration waveform associated with the vibration. The printer can determine the ink end by detecting the output signal. As a material of the piezoelectric layer, lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), a lead-less piezoelectric film that does not use lead, or the like can be used.

  The sensor chip 132 is integrally fixed to the sensor base 141 by the adhesive layer 132D by placing the lower surface of the chip body on the center of the upper surface of the sensor base 141. The sensor base 141 and the sensor chip are simultaneously fixed by the adhesive layer 132D. Between 132 is sealed.

(Ink storage section and moving member)
11 is a plan view showing a state in which the moving member 300 is arranged in the ink storage unit 200, FIG. 12 is a cross-sectional view along the X-axis direction of FIG. 11, and FIG. 13 is arranged in the ink storage unit 200. A sensor chip 132 and a moving member 300 as piezoelectric elements are shown.

  The ink reservoir 200 has an ink inlet 202 as a liquid inlet and an ink outlet 204 as a liquid outlet. The ink inlet 202 communicates with a connection needle 111a shown in FIG. As shown in FIG. 12, the ink outlet 204 communicates with the ink outlet member 109 via the inclined channel 206.

  A welding rib 208 </ b> A is formed on the end surface of the peripheral wall 208 that partitions the ink storage unit 200. A sealing film 156 (see FIG. 7) as a flexible diaphragm is welded to the welding rib 208A. The ink storage unit 200 closed by a sealing film 156 as a diaphragm forms a pressure chamber, and the sealing film 156 as a diaphragm has an ink pressure or pressure applied between the ink inlet 202 and the ink outlet 204. The pressure is displaced according to the fluid pressure.

  At the center position of the ink storage unit 200, an opening 210 is formed in which the sensor base 141 shown in FIG. As shown in FIG. 13, the sensor base 141 and the moving member 300 to which a sensor chip 132 as a piezoelectric element is fixed are arranged facing the opening 210. 13 is referred to as a sensor cavity seal surface 310A as a detection space portion seal surface. The lower end surface (310A) facing the sensor cavity seal surface 141C as a detection space portion seal surface of the sensor base 141 is referred to as a sensor space seal surface 310A as a detection space portion seal surface.

  14 to 16 are a perspective view, a plan view, and a back view of the moving member 300, respectively. The moving member 300 includes a pressure receiving plate 310. An upper end surface 312 of the pressure receiving plate 310 is welded to a sealing film 156 as a diaphragm.

  Here, directions along two orthogonal axes having an intersection at the center of the ink storage unit 200 (center of the circular pressure receiving plate 310) are defined as an X direction (first direction) and a Y direction (second direction). To do.

  The moving member 300 is provided with two shafts 320, 320 extending from the pressure receiving plate 310 toward both ends in the Y direction in FIG. The tip of each shaft 320 is formed in a curved shape, for example, a hemispherical surface 322. Further, an upstream member 330 and a downstream member 340 extending from the pressure receiving plate 310 toward both ends in the X direction in FIG. 15 are provided.

  The upstream member 330 has projecting members 332 and 334 projecting at both ends in a direction parallel to the Y direction in FIG. The back surface portion of the protruding member 332 is a first height reference surface 332A, and the back surface portion of the protruding member 334 is a second height reference surface 334A.

  The upstream member 330 further includes a first groove channel 336 as a first channel that communicates with the end opening 336A in the X direction and extends in the X direction. The inner end portion of the first groove channel 336 communicates with a first through hole 313 as a first channel formed in the pressure receiving plate 310. A second groove channel 314 as a first channel is formed on the upper end surface 312 of the pressure receiving plate 310, and the first through hole 313 and the first groove 314 face the second groove channel 314. A second through hole 315 as a flow path is formed through the pressure receiving plate 310. The second groove flow path 314 extends in the X and Y directions, and communicates the first through hole 313 existing on the X axis and the second through hole 315 existing on the Y axis. Yes.

  The third height reference surface 342 on the back surface of the downstream member 340 functions as a third height reference surface and as a first seal surface.

  The downstream side member 340 has a third groove channel 344 as a second channel formed in the third height reference surface 342 as the first seal surface. The inner end portion of the third groove channel 344 communicates with a third through hole 316 as a second channel formed in the pressure receiving plate 310. In addition, a fourth groove channel 317 as a second channel is formed on the upper end surface 312 of the pressure receiving plate 310, and the third through hole 316 and the second groove 317 face the fourth groove channel 317. A fourth through hole 318 as a flow path is formed through the pressure receiving plate 310. The fourth groove channel 317 extends in the X and Y directions, and communicates with the third through hole 316 existing on the X axis and the fourth through hole 318 existing on the Y axis. Yes.

  Here, since the sealing film 156 as a diaphragm is welded to the upper end surface 312 of the pressure receiving plate 310, the second groove channel 314 and the fourth groove channel 317 are liquid-tight with the sealing film 156 as a diaphragm. Sealed. Further, as shown in FIGS. 14 and 15, grooves are also formed on the upper end surfaces of the upstream member 330 and the downstream member 340, which is to prevent sink marks during injection molding.

  The first groove flow path 336, the second groove flow path 314, the first through hole 313, and the second through hole 315 formed in the upstream side member 330 and the pressure receiving plate 310 are referred to as the first flow path. Collectively. Similarly, the third groove flow path 344, the fourth groove flow path 317, the third through hole 316, and the fourth through hole 318 formed in the downstream side member 340 and the pressure receiving plate 310 are passed through the second flow path. Collectively. The first flow path communicates with a first through hole 141A as a supply path formed in the sensor base 141 shown in FIG. 9, and the second flow path is formed in the sensor base 141 shown in FIG. It communicates with the second through hole 141B as a discharge path. In this state, the third height reference surface 342 serving as the first seal surface is in contact with the second seal surface 244 of the ink storage unit 200, so that the third groove flow path 344 has the ink flow. Since it functions as a pipe line generally connected to the outlet 204, ink flows from the first through hole 313 when sucked from the ink outlet 127.

  At the initial stage when the ink is introduced into the ink storage unit 200, the first flow path and the second flow path are established, and the first flow path and the first flow path are generated by capillary action and suction from the ink outlet 127. Ink flows into the through hole 141A, the sensor cavity 132A (see FIG. 10), the second through hole 141B, and the second flow path, and the sensor cavity 132A is filled with ink. In this sense, the moving member 300 can also be referred to as a flow path forming member. Thereby, in any state of FIGS. 1A to 1C, at least the sensor cavity 7a is filled with ink, and air can be prevented from being mixed and erroneously detected.

(Positioning of moving member)
The positioning structure of the moving member 300 will be described with reference to FIG. In FIG. 11, the intersection of the two orthogonal axes in the X and Y directions coincides with the center position of the ink storage unit 200. As shown in FIG. 11, the ink storage unit 200 is provided with a first bearing 220 and a second bearing 224 for positioning the two shafts 320 and 320 of the pressure receiving plate 310 (FIG. 8A). See also). The first bearing 220 has two upright members 221 and 222 that rise from the ink storage unit 200 on both sides of one shaft 320. The second bearing 224 has two upright members 225 and 226 that stand up from the ink storage unit 200 on both sides of the other shaft 320.

  FIG. 13 shows a first bearing 220, for example, and the distance between the two upright members 221 and 222 is smaller than the dimension D2 indicating the distance on the proximal end side than the dimension D2 indicating the distance on the free end side (dimension D1). <Dimension D2) It is formed. The second bearing 224 is also the same size as the first bearing 220.

  Here, the diameter of the shaft 320 of the pressure receiving plate 310 is slightly smaller than the dimension D1. Therefore, the moving member 300 is positioned in the X direction shown in FIG. 11 by the two shafts 320 of the pressure receiving plate 310, the first bearing 220 and the second bearing 224 that receive the shafts 320.

  On the other hand, in order to position the moving member 300 in the Y direction, facing members 234 and 236 facing the hemispherical surface 322 that is the tip of the two shafts 320 protruding from the pressure receiving plate 310 are provided in the ink storage unit 200. It has been. Here, as shown in FIG. 8A, the ink storage unit 200 is formed with a recess 230 in which the moving member 300 is accommodated. The facing members 234 and 236 are formed on a part of the inner surface 232 that forms the recess.

  Although the inner surface 232 is a peripheral surface, the facing members 234 and 236 formed on a part thereof are formed as flat surfaces having a predetermined width W in the X direction of FIG. 11 (FIG. 8A). See also).

  Thus, since the facing members 234 and 236 are flat surfaces with a width W, the distance between the two facing members 234 and 236 is constant. Here, if there is a slight dimensional difference between the dimension D1 in the case of the minimum distance between the first bearing 220 and the second bearing 224 and the diameter of the shaft 320, the moving member 300 is displaced in the X direction. However, if it is within the range of the width W, the deviation in the Y direction is within a certain range.

  Furthermore, since the hemispherical surface 322 that is the tip of the two shafts 320 of the pressure receiving plate is a curved surface, for example, a hemispherical surface, it makes point contact with the facing members 234 and 236. Therefore, even if the moving member 300 is displaced while the hemispherical surface 322 that is the tip of the two shafts 320 of the pressure receiving plate is in contact with the facing members 324 and 326, the frictional resistance is extremely small. For this reason, the displacement of the moving member 300 according to the ink pressure or the pressurized fluid pressure in the ink storage unit 200 is not hindered.

  Thus, the moving member 300 is positioned so that the center of the moving member 300 substantially coincides with the intersection of the orthogonal two axes X and Y that are the center of the ink storage unit 200. Therefore, the positional accuracy of the moving member 300 with respect to the ink storage unit 200 is improved. This improvement in positional accuracy is extremely important in filling the sensor cavity 132A with ink at the initial stage when the ink is introduced into the ink storage unit 200, and the reason will be described later.

  Next, positioning of the moving member 300 in the height direction will be described. As described above, as shown in FIGS. 13 and 16, the upstream member 330 of the moving member 300 includes the protruding members 332 and 334, and the back surface portion of the protruding member 332 is the first height reference surface 332 </ b> A. The back surface portion of the protruding member 334 serves as a second height reference surface 334A. Further, the third height reference surface 342 on the back surface portion of the downstream side member 340 of the moving member 300 is a third height reference surface and functions as a first seal surface.

  On the other hand, as illustrated in FIGS. 8 and 11, the ink storage unit 200 includes a first height reference surface 332 </ b> A as a first seal surface of the moving member 300 and a second height as a first seal surface. Reference surface 334A, third height as a first seal surface, first height reference surface 240 as a second seal surface in contact with reference surface 342, and second height as a second seal surface The reference surface 242 has a third height reference surface 244 as a second seal surface. As described above, the moving member 300 is in contact with the three first height reference surfaces 240, the second height reference surfaces 242, and the third height reference surfaces 244, and stably sets the height position. be able to.

  Here, the third height reference surface 342 on the back surface of the downstream member 340 of the moving member 300 functions as a first seal surface, and at the initial stage when ink is introduced into the ink storage unit 200, A third height reference surface and in contact with the second seal surface. As a result, the fourth groove channel 317 of the downstream member 340 of the moving member 300 is sealed. Sealing the fourth groove channel 317 of the downstream member 340 is extremely important for filling the sensor cavity 132A with ink by capillary action and suction from the ink outlet 127 at the initial stage. Because, the first height reference surface 332A, the second height reference surface 334A, the third height reference surface 342 that form the first seal surface, and the first height that forms the second seal surface. If the sealing properties of the height reference surface 240, the second height reference surface 242, and the third height reference surface 244 are poor, the capillary action and the function as a conduit at the time of suction from the ink outlet 127 are hindered. This is because ink flows along a flow path other than the first flow path and the second flow path of the moving member 300 described above. Once the flow path is removed, the moving member 300 is displaced together with the sealing film 156 as a diaphragm, so that the first height reference surface 332A, the second height reference surface 334A, the first sealing surface, 3, and the first height reference surface 240, the second height reference surface 242, and the third height reference surface 244 forming the second seal surface are not in contact with each other. Then, the first height reference surface 332A, the second height reference surface 334A, the third height reference surface 342, which form the first seal surface, and the first height, which forms the second seal surface. This is because the reference surface 240, the second height reference surface 242, and the third height reference surface 244 do not come into contact with each other. As a result, the sensor cavity 132A is not filled with ink, and the remaining amount of ink cannot be detected.

  In this sense, the improvement in the positional accuracy of the moving member 300 with respect to the ink storage unit 200 is extremely important in filling the sensor cavity 132A with ink at the initial stage when the ink is introduced into the ink storage unit 200. That can be realized. Accordingly, in each of the states A to C in FIGS. 1A to 1C, the sensor cavity 7a is always filled with ink, so that erroneous detection of each state is reduced.

  In addition, the first height reference surface 332A, the second height reference surface 334A, the third height reference surface 342 forming the first seal surface, and the first height reference forming the second seal surface. The surface 240, the second height reference surface 242, and the third height reference surface 244 can also be referred to as a bubble discharge seal surface. That is, the first height reference surface 332A, the second height reference surface 334A, the third height reference surface 342 forming the first seal surface, and the first height reference forming the second seal surface. When the surface 240, the second height reference surface 242, and the third height reference surface 244 are securely sealed, they remain in the sensor cavity 132A as the detection space due to capillary action and suction from the ink outlet 127. This is because it is easy to remove bubbles.

  Note that the first height reference surface 332A, the second height reference surface 334A, the third height reference surface 342, and the second seal surface, which form the first seal surface, are detected at the time of liquid detection and at the initial stage. The seal load with which the first height reference surface 240, the second height reference surface 242, and the third height reference surface 244 come into contact is only the urging force of the spring 153 as the urging member shown in FIG. Can be secured. If it carries out like this, it is not necessary to provide external forces other than the spring 153 as an urging | biasing member in the initial stage.

(Positioning of sensor base and detector)
Next, the positioning of the sensor base 141 shown in FIG. 10 and the sensor chip 132 as a piezoelectric element mounted thereon will be described.

  As described above, the ink storage unit 200 as the liquid storage unit has the opening 210 that exposes one surface of the sensor base 141. The opening 210 has abutting surfaces 212 at three locations each time one surface of the sensor base 141 abuts. When one surface of the sensor base 141 comes into contact with the contact surface 212, the mounting height of the sensor base 141 and the sensor chip 132 is positioned.

  The opening 210 of the ink storage unit 200 as a liquid storage unit has an inner peripheral wall 210 </ b> A having a contour shape corresponding to the outer shape of the sensor base 141. Further, around the opening 210, there is a welding allowance 214 to be welded to the sensor sealing film 142.

  The height of the sensor base 141 inserted into the opening 210 is positioned by contacting the contact surface 212 of the opening 210 of the ink storage unit 200, and the two-dimensional plane position thereof is positioned by the inner peripheral wall 210A. Since the intersection of the orthogonal two axes X and Y is set at the center of the opening 210, the center of the sensor chip 132 mounted on the sensor base 141 is also set as the intersection of the orthogonal two axes X and Y.

  Here, in FIG. 13, the pressure receiving plate 310 has a detection space portion seal from the first height reference surface 332 </ b> A, the second height reference surface 334 </ b> A, and the third height reference surface 342 that form the first seal surface. A design value of the distance to the sensor cavity seal surface 310A as a surface is defined as a distance L1. The ink storage unit 200 determines the distance from the first height reference surface 240, the second height reference surface 242, and the third height reference surface 244 that form the second seal surface to the contact surface as a distance L2. To do. At this time, the following expression (1) is satisfied.

L1> L2 (1)
The meaning of equation (1) will be described with reference to FIG. 17, the meaning of L1> L2 means that the sensor cavity seal surface 310A of the pressure receiving plate 310 overlaps below the sensor cavity seal surface 141C of the sensor base 141. Actually, the pressure receiving plate 310 and the sensor base 141 do not overlap as shown in FIG. 17, and the sensor base 141 is bent downward by an overlap amount due to the flexibility of the sensor sealing film 142, and the sensor cavity seal of the pressure receiving plate 310 is The surface 310A securely contacts the sensor cavity seal surface 141C of the sensor base 141.

  The distances L1 and L2 will be described more specifically. When the design reference value of the distances L1 and L2 is L0, and the maximum positive variation of the distance L1 is L01, the distance L2 is designed as L0 <L1 <L0 + L01. When the maximum value of the negative variation of-is L02, L0-L02 <L2 <L0 is designed. However, L02 <L01.

  In this case, the following formula (2) is established.

L02 <L1-L2 <L01 (2)
If expression (2) is satisfied, expression (1) is always satisfied. That is, the difference between the distance L1 and the distance L2 may be between the absolute value | L2 | of the maximum negative variation of the distance L2 and the absolute value | L1 | of the maximum positive variation of the distance L1. .

(Operation at initial time and liquid detection)
At the initial stage when ink is introduced into the ink storage unit 200, the moving member 300 is displaced by the urging force of the spring 153 as the urging member, and the sensor cavity seal surface 310A of the pressure receiving plate 310 is replaced with the sensor cavity seal surface 141C of the sensor base 141. The sealing film 156 as a diaphragm is displaced to a position where the volume of the ink storage unit 200 is reduced. This state is shown in FIG. When ink starts to be introduced into the ink storage unit 200, the flow in the first flow path and the second flow path is realized as shown in FIG. 18, and the sensor cavity 132A is filled with ink. If bubbles are generated in the sensor cavity 132A, the bubbles are discharged by the second flow path on the downstream side. Thus, in each state of FIGS. 1A to 1C, it can be ensured that no bubbles exist in the sensor cavity 7a, and erroneous detection is prevented.

  On the other hand, in the pressurized state, unlike FIG. 18, the ink pressure or the pressurized fluid pressure in the ink storage unit 200 is large. Therefore, the sealing film 156 as a diaphragm expands to increase the volume of the ink storage unit 200, and the pressure receiving plate 310 is placed against the sensor cavity seal surface of the sensor base 141 against the biasing force of the spring 153 as a biasing member. 1C (state of FIG. 1 (B or FIG. 1C)) In the non-pressurized state where the ink pressure is lower than a predetermined value, the moving member 300 is displaced by the biasing force of the spring 153 as the biasing member, The pressure receiving plate 310 is brought into contact with the sensor cavity seal surface 141C of the sensor base 141, and the sealing film 156 as a diaphragm is displaced to a position where the volume of the liquid detection chamber becomes small, which is the same as FIG. (A) state).

  Although the present embodiment has been described in detail as described above, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings.

  In addition to the detection of the remaining amount of liquid, the purpose of liquid detection may be, for example, detection of liquid pressure.

  Furthermore, the liquid detection means is not limited to the piezoelectric detection means. In short, it is only necessary to detect the displacement of the moving member 300 that is displaced by the liquid pressure.

  The use of the liquid container of the present invention is not limited to the ink cartridge of the ink jet recording apparatus. The present invention can be used for various liquid consuming devices including a liquid ejecting head that discharges a minute amount of liquid droplets.

  Specific examples of the liquid consuming device include, for example, an electrode material (conducting material) used for forming an electrode such as a device having a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and a surface emitting display (FED) Examples thereof include an apparatus having a paste) ejection head, an apparatus having a bio-organic matter ejection head used for biochip manufacturing, an apparatus having a sample ejection head as a precision pipette, a textile printing apparatus, and a micro dispenser.

  In the present invention, the liquid may be any material that can be ejected by the liquid consuming device. A typical example of the liquid is ink as described in the above embodiment. The liquid may be a substance other than a material used for printing characters and images, such as liquid crystal. In the present invention, the liquid is not limited to a liquid as one state of a substance, but may be a liquid obtained by mixing a solid substance such as a pigment or metal particles with a liquid as one state of a substance.

(A)-(C) are the schematic diagrams for demonstrating the principle of this invention. (A)-(C) are figures which show typically an output waveform corresponding to Drawing 1 (A)-Drawing 1 (C). FIG. 3 is a diagram illustrating an example of an ink cartridge to which the present invention is applied. FIG. 4 is a diagram illustrating another example of an ink cartridge to which the present invention is applied. 1 is a perspective view of a printer in an embodiment of the present invention. FIG. 6 is an exploded perspective view of the printer shown in FIG. 5. The disassembled perspective view of a liquid detection unit. (A) And (B) is a schematic perspective view of the case main body of a liquid detection unit. The perspective view which looked at the sensor base from the back. The perspective view which looked at the sensor base with which the sensor chip was mounted from the table | surface. The top view of an ink storage part. Sectional drawing along the Y-axis of FIG. Schematic explanatory drawing for demonstrating attachment of the moving member, a sensor base, and a detection part to an ink storage part. The schematic perspective view of a moving member. The top view of a moving member. The back view of a moving member. The B section enlarged view of FIG. FIG. 3 is a schematic cross-sectional view for explaining an initial operation and an ink detection operation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,111 ... Ink detection unit as a detection apparatus, 2 ... Ink detection unit case, 3 ... Film, 4 ... Ink storage part as a liquid storage part, 5 ... Moving member, 6 ... Sensor base, 6a, 6b ... Hole, DESCRIPTION OF SYMBOLS 7 ... Sensor chip as a piezoelectric element, 7a ... Sensor cavity, 23 ... Ink cartridge, 100 ... Ink as liquid, 101 ... Pressurized fluid (for example, air), 105 ... Case main body as a sub tank, 107 ... Ink storage part, DESCRIPTION OF SYMBOLS 115 ... Film, 121 ... Lid, 127 ... Ink outlet as liquid outlet, 128 ... Pressurized fluid inlet, 129 ... Ink inlet, 130 ... Main tank, 131 ... Pressure pump, 132 ... Piezoelectric element Sensor chip, 132A ... sensor cavity as detection space, 132C ... piezoelectric element, 141 ... detector installation member 141A ... first through hole as supply path, 141B ... second through hole as discharge path, 141C ... sensor cavity seal surface as detection space seal surface, 142 ... sensor sealing film 153, a spring as an urging member, 156, a sealing film as a diaphragm, 200, an ink reservoir as a liquid reservoir, 202, an ink inlet as a liquid inlet, and 204, an ink flow as a liquid outlet. Outlet, 220 ... first bearing, 224 ... second bearing, 230 ... recess, 234, 236 ... facing member, 240 ... first height reference surface as a second sealing surface, 242 ... second Second height reference surface as a sealing surface, 244 ... Third height reference surface as a second sealing surface, 300 ... Moving member, 310 ... Pressure receiving plate, 320 ... Shaft, 330 ... Upstream 340 ... downstream member, 336 ... first groove channel as first channel, 313 ... first through hole as first channel, 314 ... second as first channel ,... 315... Second through hole as a first flow path, 344... Third groove flow path as a second flow path, 316... Third through hole as a second flow path. 317: a fourth groove channel as a second channel, 318: a fourth through hole as a second channel, 332A: a first height reference surface as a first seal surface, 334A ... a second height reference surface as the first seal surface, 342 ... a third height reference surface as the first seal surface.

Claims (20)

A liquid containing part that discharges the liquid by introducing a pressurized fluid into the region containing the liquid; and
A liquid outlet for supplying liquid from the liquid container to the liquid consuming device;
A detection device provided between the liquid container and the liquid outlet;
Have
The detection device includes:
A liquid storage part provided between the liquid storage part and the liquid outlet;
Applying a vibration to a sensor cavity that communicates with the liquid reservoir and receives the liquid, and detects a state of free vibration associated with the vibration; and
A moving member that is displaced in response to a pressurized state in the liquid storage section at a position facing the sensor cavity;
A liquid container, comprising: The pressurized fluid is different from the liquid,
The piezoelectric element outputs a different signal based on the difference between the liquid and the pressurized fluid when the medium in the region between the sensor cavity and the moving member is pressurized when the liquid container is pressurized. The liquid container according to claim 1.   The frequency of the free vibration of the piezoelectric element is different based on whether a medium in a region between the sensor cavity and the moving member is the liquid or the pressurized fluid. The liquid container described in 1.   The amplitude of the free vibration of the piezoelectric element is different based on whether a medium in a region between the sensor cavity and the moving member is the liquid or the pressurized fluid. The liquid container described in 1. During non-pressurization at the time of liquid storage, one surface of the moving member makes the sensor cavity a closed space,
5. The liquid container according to claim 2, wherein the piezoelectric element outputs different signals depending on whether the liquid container is pressurized or not. 5.   The liquid container according to claim 5, wherein the piezoelectric element has different amplitudes of the free vibration depending on whether the liquid container is pressurized or not.   6. The method according to claim 5, wherein when the liquid container is pressurized and non-pressurized is detected based on a combination of each value of the frequency and amplitude of the free vibration output from the piezoelectric element. Liquid container.   The liquid container according to claim 2, wherein the pressurized fluid is air. The pressurized fluid is the liquid, and at the time of non-pressurization when the liquid is stored, one surface of the moving member makes the sensor cavity a closed space,
The liquid storage container according to claim 1, wherein the piezoelectric element outputs different signals depending on whether the liquid storage unit is pressurized or not.   The liquid storage container according to claim 9, wherein the piezoelectric element has different amplitudes of the free vibration when the liquid storage portion is pressurized and when it is not pressurized.   10. The method according to claim 9, wherein when the liquid container is pressurized and non-pressurized is detected based on a combination of each value of the frequency and amplitude of the free vibration output from the piezoelectric element. Liquid container.   The liquid storage unit is configured by sealing an opening formed on an upper surface with a film that can be deformed according to a pressurized state, and the piezoelectric element is disposed at the bottom of the liquid storage unit. The liquid container according to any one of claims 1 to 11.   The liquid container according to claim 12, wherein the moving member moves by deformation of the film corresponding to a change in a pressurized state of the liquid storage unit.   The liquid container according to claim 13, wherein the moving member is fixed to the film.   The liquid container according to claim 14, wherein the moving member is biased by a biasing member in a direction in which the piezoelectric element is disposed. A liquid storage unit that discharges the liquid by introducing a fluid into the same region as the region in which the liquid is stored;
A liquid outlet for supplying liquid from the liquid container to the liquid consuming device;
A detection device provided between the liquid container and the liquid outlet;
Have
The detection device includes:
A liquid storage part provided between the liquid storage part and the liquid outlet;
Applying a vibration to a sensor cavity that communicates with the liquid reservoir and receives the liquid, and a piezoelectric element that is in a free vibration state associated with the vibration; and
A moving member that is displaced in response to a pressure state in the liquid storage unit at a position facing the sensor cavity;
A liquid container, comprising:   The piezoelectric element outputs a different signal based on whether the medium in the region between the sensor cavity and the moving member when the fluid is introduced into the liquid container is the liquid or not the liquid. The liquid container according to claim 16, wherein the liquid container is a liquid container.   The free vibration of the piezoelectric element has a different frequency or amplitude based on whether a medium in a region between the sensor cavity and the moving member is the liquid or the liquid. The liquid container described.   The liquid container according to claim 16, wherein the free vibration of the piezoelectric element has a different frequency or amplitude when the fluid is introduced and when the fluid is not introduced.   The liquid container according to claim 16, wherein the liquid container includes a main tank and a sub tank, and the fluid is introduced into the sub tank via the main tank.