JP2008238666A - Liquid detection apparatus and liquid container using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid detection apparatus provided with a function to detect a liquid with high precision in such a way as to detect that a remaining quantity or a pressure of a liquid becomes a predetermined value. <P>SOLUTION: The liquid detection apparatus 11 is provided with: a liquid inflow port 104; a liquid outflow port 105; and a diaphragm 101 to displace according to a liquid pressure between the ports. The apparatus also has: a liquid detection chamber 102 whose volume is changed according to a liquid pressure; a moving member 110 mounted onto the diaphragm 101, which is oscillated and displaced on an oscillating shaft 111 as a center in the liquid detection chamber 102; and a torsion coil spring 120 which moves and energizes the moving member 110, and displaces the diaphragm 101 so that the volume of the liquid detection chamber 102 is reduced when the liquid pressure is decreased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid detection device having a moving member that is displaced in accordance with a liquid pressure or a liquid volume in a liquid detection chamber, and a liquid storage container using the same.

  Liquid ejecting heads in liquid ejecting apparatuses such as textile printing apparatuses, micro dispensers, and commercial recording apparatuses that require ultra-high quality printing are supplied with liquid to be ejected from the liquid container, but are supplied with liquid. If it is operated in a state where it is not in operation, the jet head is damaged due to so-called idle driving, and it is necessary to monitor the remaining amount of liquid in the container in order to prevent this.

  Thus, taking an example of a recording apparatus, various types of ink cartridges that are liquid containers and equipped with a liquid detection unit for detecting the remaining amount of ink have been proposed.

As a specific configuration of such a liquid detection unit, as in the invention described in Patent Document 1, a recess for storing liquid is provided on one of opposing flat surfaces of a flexible bag that stores liquid. And forming a piezoelectric vibrator on the outer surface of the recess, and a rigid body on the other surface, and detecting from the vibration state due to the amount of liquid (depth of liquid) between the rigid body and the piezoelectric vibrator. Has also been proposed.
JP 2004-136670 A

  However, although the liquid detection unit described in Patent Document 1 can detect the remaining amount of liquid with relatively high accuracy, the remaining amount of ink stored in the flexible bag is changed to the deformation of the flexible bag. Since the rigid body is moved by following the movement, there is a possibility that the detection accuracy may be lowered due to the influence of the bag bending, wrinkles and the like.

  Accordingly, an object of the present invention is to eliminate the above-described problem, and a liquid detection device having a function of detecting a liquid with high accuracy, such as that the remaining amount of liquid or pressure reaches a predetermined value, and the same are used. It is to provide a liquid container.

A liquid detection apparatus according to an aspect of the present invention includes:
A liquid inlet, a liquid outlet, a flexible diaphragm that is displaced according to a liquid pressure between the liquid inlet and the liquid outlet, and a detector installed so as to face the diaphragm A liquid detection chamber, the volume of which varies according to the liquid pressure,
A moving member provided in the liquid detection chamber;
A detection space provided on the detection portion installation surface, comprising: a detection space communicating with the liquid detection chamber; and a piezoelectric sensor for detecting a residual vibration waveform associated with the vibration by applying vibration to the detection space. And
Have
The moving member has a swing shaft and a pressure receiving plate provided at a position away from the swing shaft,
A part of the moving member is attached to the diaphragm,
The pressure receiving plate is opposed to the detection unit installation surface,
The moving member swings around the swing shaft to displace the pressure receiving plate,
The moving member is biased toward the detection space by a spring,
When the liquid pressure is a predetermined value, the diaphragm expands until the volume of the liquid detection chamber reaches a predetermined volume, and the pressure receiving plate is installed on the detection unit against the urging force of the spring. Away from the surface,
The moving member brings the pressure receiving plate into contact with the detection installation surface by the biasing force of the spring when the liquid pressure falls below the predetermined value, and the volume of the liquid detection chamber is set to the predetermined value. Displace the diaphragm to a position that is smaller than the volume,
The piezoelectric sensor detects the residual vibration waveform based on a distance between the piezoelectric sensor and the pressure receiving plate.

  According to one aspect of the present invention, a part of the moving member biased by the spring is attached to the flexible diaphragm. When the liquid pressure in the liquid detection chamber is high, the diaphragm expands to increase the volume of the liquid detection chamber, and the pressure receiving plate is separated from the detection unit installation surface against the urging force of the spring. When the liquid pressure falls below a predetermined value, the moving member is displaced by the urging force of the torsion coil spring to bring the pressure receiving plate into contact with the detection installation surface, and the diaphragm is displaced to a position where the volume of the liquid detection chamber is reduced. . When the pressure receiving plate is separated from the detection unit installation surface and the detection space is opened to the liquid detection chamber, the residual vibration waveform is less attenuated. On the other hand, when the pressure receiving plate contacts the detection installation surface and the detection space is closed, the residual vibration waveform is greatly attenuated. From this difference, liquid detection such as the remaining amount of liquid and pressure is possible based on the position of the moving member. At this time, the moving member swings in conjunction with the movement of the flexible diaphragm. The moving member swings around the swing shaft. Therefore, the pressure receiving plate can be stably displaced, and the liquid can be detected with high accuracy.

  When liquid is detected by the residual waveform of the piezoelectric sensor, it is preferable to detect the amplitude value of the residual vibration waveform that changes based on the distance between the piezoelectric sensor and the pressure receiving plate. Rather than counting the decay time and wave number of the residual vibration waveform, the residual liquid pressure and pressure can be accurately measured by measuring the amplitude of the residual vibration waveform after excitation for a certain period of time and comparing it with a threshold value. And it can measure simply.

  In one aspect of the present invention, the liquid detection chamber is preferably formed with a recess in which the moving member and the spring are accommodated, and the opening end of the recess is sealed with the diaphragm. Since the moving member requires a predetermined pressure receiving area, a sufficient space in which a spring such as a torsion coil spring can be arranged can be secured in the liquid detection chamber sealed by the diaphragm. Therefore, since the size of the liquid detection chamber does not increase and it is not necessary to arrange a spring outside the liquid detection chamber, the liquid detection device can be downsized.

  In one aspect of the present invention, it is preferable that the swing shaft is integrally formed with the moving member, and the swing shaft is rotatably supported by the liquid detection chamber. By integrating the swing shaft with the moving member, the number of parts is reduced and assembly is facilitated.

  1 aspect of this invention WHEREIN: The said pressure receiving plate has the 1st surface facing the said detection part installation surface, and the 2nd surface facing the said diaphragm, The said diaphragm is the said pressure plate | board of the said pressure receiving plate. It is preferable to be fixed to the second surface. By using the second surface of the pressure receiving plate as a diaphragm fixing portion, there is no need to separately provide a diaphragm fixing portion on the moving member, and the liquid detection device can be further miniaturized. At this time, if the moving member is attached to the diaphragm by welding at least a part of the second surface of the pressure receiving plate to the diaphragm, the assembly of the liquid detection device is facilitated.

  In one aspect of the present invention, the spring is preferably a torsion coil spring. The load applied by the torsion coil spring to the moving member is not as great as the compression or tension coil spring proportional to the displacement of the moving member. Therefore, the accuracy of the design pressure that becomes a threshold when the moving member moves to the moving end is increased. Liquid detection such as the remaining amount of liquid or pressure is determined by the position of the moving member, and the positional accuracy of the moving member corresponding to the remaining amount or pressure is increased. As a result, the detection accuracy can be further increased.

  In one aspect of the present invention, it is preferable that the torsion coil spring is supported by being inserted through the swing shaft. Since the torsion coil springs can be inserted into the swing shaft integrated with the moving member and placed in the liquid detection chamber, assembly is facilitated.

  In one aspect of the present invention, it is preferable that one end side of the swing shaft in the axial direction is fixed to the diaphragm. As a result, the swing shaft is stably held at a predetermined vertical position in the liquid detection chamber. Therefore, the movement of the moving member can be stabilized, and as a result, the detection accuracy can be further increased.

  In one aspect of the present invention, it is preferable that the torsion coil spring is inserted through the swing shaft in a range that is biased toward the other end side in the axial direction of the swing shaft. In this way, the vertical position on one end side of the rocking shaft can be regulated by the diaphragm, while the vertical position on the other end side can be regulated by the torsion coil spring, making the position of the rocking shaft more stable and improving detection accuracy. It becomes possible to aim to improve.

  In one aspect of the present invention, the moving member includes an upstream member extending from the pressure receiving plate toward the liquid inlet side along a direction intersecting the swing shaft, and the swing shaft. A downstream member extending from the pressure receiving plate toward the liquid outlet side along the intersecting direction, and the swing shaft is integrally formed in the middle of the upstream portion, It is preferable that the distance from the rocking shaft to the free end of the upstream portion is shorter than the distance from the rocking shaft to the free end of the downstream portion. If it carries out like this, the displacement of a moving member does not oppose the flow of a liquid, and can displace a moving member smoothly. Therefore, the detection accuracy can be further increased.

  In one aspect of the present invention, it is preferable that the liquid detection chamber has a guide portion that moves and guides the downstream portion. By guiding the downstream portion having a large displacement amount by the guide portion, the moving member can be displaced more smoothly as the liquid pressure changes. Therefore, the detection accuracy can be further improved.

  In one aspect of the present invention, the pressure receiving plate and the upstream portion have a first flow path that guides liquid from the liquid inlet to the detection space, and the pressure receiving plate and the downstream portion are liquid. It is preferable to have a second flow path that guides the liquid from the detection space to the liquid outlet. With such a configuration, the operation of filling the liquid detection device with the liquid by sucking the liquid from the liquid outlet side is in a state where the pressure receiving plate is in contact with the detection installation surface, that is, the detection space is closed. If it is performed in the state, the suction force easily acts on the liquid inlet 104 from the liquid outlet. Therefore, generation | occurrence | production of the bubble in a detection space part can be prevented. In addition, the liquid in the liquid detection chamber is easily sucked, and bubbles remaining in the detection space can be easily removed. In other words, the detection space portion, which is the vibration action area, is reliably filled with liquid and bubbles do not remain in the detection space portion. Detection is possible.

A liquid container according to another aspect of the present invention includes a liquid container that discharges liquid stored under pressure by a pressurizing unit from a liquid discharge port,
The liquid detection device described above in which the liquid discharge port communicates with the liquid inlet;
It is characterized by having.

  If the liquid detection device described above is used, the presence or absence of liquid in the liquid storage unit can be accurately detected, which is suitable for end detection or near end detection of the remaining amount of liquid.

  Hereinafter, a liquid container provided with a liquid detection device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking an ink cartridge as an example. 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.

(Liquid container)
FIG. 1 is an exploded perspective view of a liquid container 1 according to the present embodiment. The liquid container 1 is an ink cartridge that is detachably mounted on a cartridge mounting portion of an ink jet recording apparatus (liquid consumption apparatus) (not shown) and supplies ink (liquid) to a print head mounted on the recording apparatus. .

  As shown in FIG. 1, the liquid storage container 1 includes a container main body 5 in which a pressurizing chamber 3 pressurized by a pressurizing unit (not shown) is formed, and ink stored by pressurization of the pressurizing chamber 3. And an ink supply port (liquid supply) for supplying ink to a print head of an ink jet recording apparatus which is an external liquid consuming device. (Mouth) 9, and an ink detection unit (liquid detection device) 11 that is interposed between the ink pack 7 and the ink supply port 9 and detects the remaining amount of ink.

  The container main body 5 is a housing formed by resin molding. The container body 5 is partitioned into a substantially box-shaped bag body housing portion 3a having an open upper portion and a detection unit housing portion 13 for housing the ink detection unit 11 located on the front side of the bag body housing portion 3a. Has been.

  The open surface of the bag body accommodating portion 3 a is sealed with the sealing film 15 after the ink pack 7 is accommodated. Thereby, the pressurizing chamber 3 becomes a sealed chamber.

  The partition wall 5a partitioning the bag body housing portion 3a and the detection unit housing portion 13 is for supplying pressurized air into the pressurizing chamber 3 formed in the sealed chamber by the sealing film 15. The pressurizing port 17 which is a communication path is equipped. When the liquid container 1 is mounted on the cartridge mounting portion of the ink jet recording apparatus, the pressurized air supply means on the cartridge mounting portion side is connected to the pressurizing port 17, and ink is supplied by the pressurized air supplied into the pressurizing chamber 3. The pack 7 can be pressurized.

  The ink pack 7 is obtained by joining a cylindrical ink lead-out member 7a into which the connection needle 11a of the ink detection unit 11 is inserted and connected to one end side of a flexible bag 7b formed of a multilayer sealing film. . The ink pack 7 ensures high gas barrier properties by using, for example, an aluminum laminated multilayer film.

  The ink lead-out member 7a of the ink pack 7 is hermetically inserted through the connection port insertion opening 18 formed in the partition wall 5a, and its tip protrudes into the detection unit housing portion 13.

  Here, the sealing film 8 is welded to the ink lead-out member 7a. The sealing film 8 is welded to the opening end face of the ink lead-out member 7 and the end face of a seal member (not shown) disposed on the ink lead-out member 7a to prevent ink leakage.

  Before the ink detection unit 11 is connected, the ink pack 7 is filled with ink that has been adjusted to a high degree of deaeration in advance and is sealed with a sealing film 8.

  When the ink pack 7 is attached to the bag body accommodating portion 3a, the resin spacer 19 is attached on the front and rear inclined portions 7c and 7d of the flexible bag 7b. The resin spacer 19 prevents the ink pack 7 from rattling in the pressurizing chamber 3 when the upper surface of the bag housing portion 3a is covered with the sealing film 15 and the pressurizing chamber 3 is sealed. To do. At the same time, an extra empty space in the pressurizing chamber 3 is filled to increase the pressurization efficiency when pressurizing the pressurizing chamber 3 with pressurized air.

  When the ink detection unit 11 is mounted in the detection unit housing portion 13, the sealing film 8 is pierced by the connection needle 11a, and a valve mechanism (not shown) disposed in the ink lead-out member 7a is connected to the connection needle. It is actuated by 11a to enable the discharge of ink. In this state, ink is filled into the detection unit 11 by sucking out ink from the ink lead-out member 11b. Thereafter, the ink lead-out member is sealed by attaching the sealing film 11c to the ink lead-out member 11b by welding or the like. The ink lead-out member 11b has the same structure as the ink lead-out member 7a of the ink pack 7. A connection needle (not shown) provided in the cartridge mounting portion of the ink jet recording apparatus is inserted into the ink lead-out member 11b by breaking the sealing film 11c. At that time, the valve mechanism arranged in the ink lead-out member 11b is actuated by the connecting needle, and ink can be led out.

  A resin cover 21 is mounted on the detection unit housing portion 13 and the sealing film 15. When the cover 21 is put on the container main body 5, the engaging means (not shown) is engaged with the engaging portion 22 on the container main body 5 side and fixed to the container main body 5.

(Ink detection unit)
2 is an exploded perspective view of the ink detection unit 11, FIG. 3 is a schematic perspective view of the ink detection unit 11 showing an assembled state excluding the diaphragm, and FIG. 4 is a schematic perspective view of the ink detection unit 11 with the diaphragm attached. FIG. FIG. 5 is a cross-sectional view of the ink detection unit 11 when the ink pack 7 is full, and FIG. 6 shows ink when the ink pack 7 is not installed and when the ink pack 7 is empty. 2 is a cross-sectional view of a detection unit 11. FIG. 5 and 6 are cross-sectional views taken along the flow path formed in the moving member 110 from the liquid inlet 104 to the liquid outlet 105.

  The ink detection unit 11 according to the present embodiment supplies ink to the ink detection chamber 102 (FIG. 3 and FIG. 5) via the connection needle 11a (FIGS. 1 and 2) on the back side of the unit main body 100 and the ink inlet 104 (FIGS. 3 and 5). 2, 3, and 5), and in the process of deriving ink through the ink outlet 105 (FIG. 5) and the ink deriving member 11 b (FIGS. 2 and 3), the remaining amount of ink is detected. .

  As can be seen from FIG. 2, the ink detection unit 11 includes a unit main body 100, a moving member 110 and a torsion coil spring 120 disposed in the unit main body 100, and a diaphragm 101 that seals the unit main body 100.

  The unit body 100 is a rigid body made of resin, for example. As can be seen from FIGS. 2 and 3, a recess 103 is formed in the unit main body 100, and the moving member 110 and the torsion coil spring 120 are accommodated in the recess 103. In addition, a protrusion 130 a is provided at the opening end of the recess 103.

  In the recess 103 of the unit main body 100, as shown in FIG. 5, an ink (liquid) inlet 104 is provided on one end side in the longitudinal direction, and an ink (liquid) outlet 105 is provided on the other end side. The ink inlet 104 communicates with the connection needle 11a (FIGS. 1 and 2) of the ink detection device 11, and the pressurized ink flows from the ink pack 7. For this reason, the ink inlet 104 is open at a position facing the connection needle 11a on the bottom surface 103a of the recess 103 of the unit main body 100. The ink outlet 105 communicates with the ink outlet member 11b (FIGS. 2 and 3) of the ink detection unit 11.

  The moving member 110 is a member that swings and displaces around the swing shaft 111 in the ink detection chamber 102. As shown in FIGS. 2 and 3, bearing portions 106 and 107 are formed in the unit main body 100. The swing shaft 111 is rotatably supported by the unit main body 101 by bearings 106 and 107.

  A pressure receiving plate 112 is provided at a position away from the swing shaft 111 of the moving member 110. As shown in FIGS. 2 and 5, the bottom surface 103 a of the recess 103 of the unit main body 110 is provided with a stepped portion 108 that is further recessed than the bottom surface 103 a. A portion on the bottom surface 103 a side of the pressure receiving plate 112 is disposed in the stepped portion 108. An ink detection unit 130 described later is provided on the bottom surface 108b (detection unit installation surface) of the stepped portion 108. A bottom surface (first surface) 112 a of the pressure receiving plate 112 faces the bottom surface 108 b of the stepped portion 108. On the other hand, the upper surface (second surface) 112 b of the pressure receiving plate 112 faces the diaphragm 101.

  Further, as shown in FIGS. 2, 3, 5, and 6, the moving member 110 includes an upstream member 113, a downstream member 114, a spring locking portion 117, and a shaft fixing portion 111a. The shaft fixing portion 111 a is formed on one end side in the axial direction of the swing shaft 111 so as to extend above the swing shaft 111. The upstream member 113 extends from the pressure receiving plate 112 toward the liquid inlet 104 along a direction intersecting (for example, orthogonal to) the swing shaft 111. The upstream member 113 intersects the swing shaft 111 at a position deviated toward one end side (the shaft fixing portion 111 a side) with respect to the axial center of the swing shaft 111. The downstream member 114 extends from the pressure receiving plate 112 toward the liquid outlet 105 along the direction intersecting (for example, orthogonal to) the swing shaft 111.

  The distance from the swing shaft 111 to the free end of the upstream member 113 is shorter than the distance from the swing shaft 111 to the free end of the downstream member 114. That is, when the moving member 110 swings, the displacement amount of the free end of the downstream member 114 is larger than the displacement amount of the free end of the upstream member 113. Therefore, the unit main body 100 includes a guide portion 109 that guides the swing of the downstream side member 114 (see FIGS. 2 and 3). Even if the amount of displacement of the downstream member 114 is large, the direction of displacement does not oppose the direction of ink flow, so that the ink hardly interferes with the displacement. On the contrary, it is not preferable to provide the swing shaft 11 in the middle of the downstream member 114 and increase the displacement amount of the upstream member 113. This is because the displacement direction of the upstream member 113 opposes the ink flow.

  In the present embodiment, the swing shaft 111, the pressure receiving plate 112, the upstream member 113, the downstream member 114, the spring locking portion 117, and the shaft fixing portion 111a constituting the moving member 110 are integrally molded. If these are integrally molded, the number of parts is reduced and assembly is facilitated. However, it is not essential to integrally mold these components. That is, some or all of these components may be formed separately.

  The pressure receiving plate 112 and the upstream side member 113 have a first flow path 115 that guides ink from a liquid inlet 104 side to a detection space 134 described later. The pressure receiving plate 111 and the downstream member 114 include a second flow path 116 that guides ink from the detection space 134 to the liquid outlet 105. As shown in FIGS. 2 and 5, in the first and second flow paths 115 and 116, the portion of the upper surface 112 b of the pressure receiving plate 112 has openings 115 a and 116 a provided in the upper surface 112 b of the pressure receiving plate 112 as diaphragms. It is formed by sealing with 101.

  The torsion coil spring 120 is inserted through the swing shaft 111 of the moving member 110. One end 121 of the torsion coil spring 120 is engaged with a corner 103b on the bottom surface 103a of the unit main body 110 as shown in FIGS. The other end 122 of the torsion coil spring 120 is locked to a bottomed spring locking portion 117 (see FIGS. 2 and 3) formed by recessing a part of the upstream member 113 of the moving member 110. . As a result, the pressure receiving plate 120 of the moving member 110 is urged to rotate in the arrow A direction (the bottom surface 108b direction) shown in FIGS.

  Diaphragm 101 is formed of a flexible resin film. As illustrated in FIG. 4, the diaphragm 101 is provided on the protrusion 130 a provided on the unit main body 100, the upper surface 112 b of the pressure receiving plate 120 of the moving member 110, and the swing shaft 111 of the moving member 110. It is attached to the shaft fixing part 111a by, for example, heat welding.

  First, the diaphragm 101 is attached to a protrusion 130 a provided on the unit main body 100. Thereby, the open end of the recess 103 of the unit main body 100 is covered with the diaphragm 101 having flexibility. As described above, the recess 103 of the unit main body 100 is covered with the flexible diaphragm 101, whereby the ink detection chamber 102 as shown in FIGS. 5 and 6 is formed.

  Diaphragm 101 is also attached to upper surface 112 b of pressure receiving plate 120 of moving member 110. As will be described later, the moving member 110 swings according to the pressure of the ink in the ink detection chamber 102, and the position of the pressure receiving plate 120 changes accordingly. Along with the displacement of the pressure receiving plate 120, the diaphragm 101 attached to the pressure receiving plate 120 is also displaced, whereby the volume of the ink detection chamber 102 changes. In the present embodiment, the upper surface 112 b of the pressure receiving plate 112 is attached to the diaphragm 101, but another portion of the moving member 110 may be attached to the diaphragm 101. In the present embodiment, almost the entire upper surface 112 b of the pressure receiving plate 112 is attached to the diaphragm 101. However, it is not necessary to attach the entire upper surface 112b of the pressure receiving plate 112 to the diaphragm 101, and it is sufficient that at least a part thereof is attached.

  Further, the diaphragm 101 is fixed to one end side of the swing shaft 111 of the moving member 110 through a shaft fixing portion 111a. On the other hand, the torsion coil spring 120 is inserted and supported by the swing shaft 111 at a position that avoids the upstream member 113. That is, the range in which the torsion coil spring 120 is inserted is a range that is biased toward the other end side in the axial direction of the swing shaft 111 (the side opposite to the shaft fixing portion 111a). The other end side of the swing shaft 111 in the axial direction is urged to rotate in the direction of arrow A shown in FIGS. 5 and 6 by the torsion coil spring 120, whereas one end side of the swing shaft 111 has the shaft fixing portion 111a. By being fixed to the diaphragm 101, the bearings 106 and 107 are stably held at predetermined vertical positions.

  In this embodiment, one end side of the swing shaft 111 is fixed to the diaphragm 101 via the shaft fixing portion 111a, but one end side of the swing shaft 111a is provided without providing such a shaft fixing portion 111a. May be directly fixed to the diaphragm 101. Further, the vertical positions of the swing shaft 111 may be regulated by partially melting and deforming the bearing portions 106 and 107. In this case, it is not necessary to fix one end side of the swing shaft 111 a to the diaphragm 101, and only the pressure receiving plate 112 of the moving member 110 may be attached to the diaphragm 101.

(Ink detection unit)
As shown in FIGS. 5 and 6, the ink detection unit 130 in the ink detection unit 11 includes ink (liquid) guide paths 131 and 132 formed through the bottom wall 108 a of the step portion 108 of the unit main body 110, and the ink guide. A detection space 134 including an ink guide path 133 communicating with the paths 131 and 132 is provided. The ink detection unit 130 further defines a detection space 134 together with the bottom wall 108 a, and has piezoelectric detection means such as a piezoelectric sensor 135 disposed facing the detection space 134.

  The piezoelectric sensor 135 applies a vibration to the detection space 134 and detects a residual vibration waveform associated with the vibration.

  The piezoelectric sensor 135 can detect different residual vibration waveforms depending on whether or not the ink guide paths 131 and 132 are covered by the pressure receiving plate 112. This detection principle is disclosed in Patent Document 1.

  As shown in FIG. 5, in the state in which the pressurized ink is supplied from the ink pack 7, if vibration is applied to the detection space 134 by the piezoelectric sensor 135, the residual shown in FIG. A vibration waveform is observed. On the other hand, as shown in FIG. 6, in the state where ink is not supplied from the ink pack 7, if vibration is applied to the detection space 134 by the piezoelectric sensor 135, for example, a residual vibration waveform shown in FIG. Is observed. Thus, the attenuation of the residual vibration waveform varies depending on the difference in the distance from the piezoelectric sensor 135 to the pressure receiving plate 112 that is a rigid body. Therefore, the empty state of the ink pack 7 shown in FIG. 6 is detected by detecting the amplitude of the residual vibration waveform when a certain time has passed after excitation by the piezoelectric sensor 135, for example, by comparing it with a threshold value. It can be detected separately from the state 5. This detection may be performed by counting the duration of the residual vibration or the wave number of the residual vibration waveform.

  In the present embodiment, the residual vibration waveform shown in the state of FIG. 6 is detected by the piezoelectric sensor 135 to detect the remaining amount of the ink in the ink pack 7 being exhausted.

(Change in ink detection chamber 102)
As shown in FIG. 6, when the liquid container 1 is not mounted on the cartridge mounting portion of the ink jet recording apparatus (unmounted state), the diaphragm 101 and the moving member 110 are moved downward by the biasing force of the torsion coil spring 101. Is located.

  Further, due to the biasing force of the torsion coil spring 120, the bottom surface 112 a of the pressure receiving plate 112 abuts on the bottom surface 108 b of the stepped portion 108, and the first and second flow paths 115 and 116 communicate with the ink guide paths 131 and 132. Yes. As a result, the detection space 134 is communicated only with the narrow first and second flow paths 115 and 116 and becomes a substantially closed space.

  As described above, the ink is filled into the detection unit 11 of the liquid container 1 before the ink is consumed by sucking out the ink from the ink outlet member 11b. This operation is performed in a state as shown in FIG. Accordingly, the suction force passes through the second flow path 116 formed in the moving member 110, the ink guide paths 131, 132, 133, and the first flow path 115, and then to the discharge port of the ink pack 7 connected to the ink detection chamber 102. Works. Therefore, the ink is guided not only to the periphery of the moving member 110 but also to the ink guiding paths 131, 132, and 133 through the first flow paths 115 and 116, and the detection space 134 is filled with the ink. In the liquid container 1 of the present embodiment, the first flow path 115 formed in the upstream member 113 extends to the vicinity of the ink inlet 104 and the second flow path formed in the downstream member 114. 116 extends to the vicinity of the ink outlet 105. For this reason, when sucking ink, the suction force easily acts on the ink inlet 104 from the ink outlet 105. Therefore, generation of bubbles in the detection space 134 can be prevented. Further, the ink in the ink detection chamber 102 is easily sucked through the ink guide paths 131, 132, and 133 communicating with the first flow path 115 and the second flow path 116, and remains in the detection space 134. This makes it easier to eliminate bubbles. That is, since the detection space part 134 that is the vibration action region is reliably filled with ink and no bubbles remain in the detection space part 134, a reduction in detection accuracy due to the remaining bubbles is prevented, and high accuracy is achieved. It is possible to detect the remaining amount of ink.

  Next, when the liquid storage container 1 is mounted on the cartridge mounting portion of the ink jet recording apparatus, the ink in the ink pack 7 is pressurized by the pressurized air to the pressurizing chamber 3 (FIG. 1) and enters the liquid inlet 104. Pumped. Since the ink is filled downstream from the liquid outlet 105, the liquid pressure between the liquid inlet 104 and the liquid outlet 105 is shown in FIG. 6 as long as the ink remains in the ink pack 7. It becomes a value larger than the unmounted state. Therefore, as shown in FIG. 5, the diaphragm 101 expands until the volume of the liquid detection chamber 102 reaches a predetermined volume, and separates the pressure receiving plate 112 from the bottom surface 108b against the biasing force of the torsion coil spring 120. Let As long as ink remains in the ink pack, the state of FIG. 5 is maintained.

  On the other hand, when the ink in the ink pack 7 runs out, there is no ink to be supplied no matter how much the pressurizing chamber 3 is pressurized, so the liquid inlet 104 to the liquid inlet 104 and the liquid outlet 105 The fluid pressure between them decreases. Therefore, as shown in FIG. 6, the moving member 110 reduces the container of the detection chamber by bringing the pressure receiving plate 112 into contact with the bottom surface 108 b and moving the diaphragm 101 downward by the biasing force of the torsion coil spring 101. Let Thereby, the detection space part 134 is communicated only with the narrow first and second flow paths 115 and 116 again, and becomes a substantially closed space.

  The area of the diaphragm 101 and the urging force of the torsion coil spring 120 are appropriately adjusted so that the pressure receiving plate 112 contacts the bottom surface 108b when the ink in the ink pack 7 runs out. The diaphragm 101 is displaced according to the pressure of ink supplied to the ink detection chamber 102. In order to detect a minute pressure change of ink and improve detection accuracy, it is preferable that the diaphragm 101 has sufficient flexibility. In addition, when the ink pressure in the ink detection chamber 102 decreases and eventually the ink in the ink pack 7 runs out, the state of FIG. 6 is mainly set by the urging force of the torsion coil spring 120, so the torsion coil spring 120. The setting of the urging force is also important.

(Swing of moving member and action of torsion coil spring)
In this embodiment, the moving member 110 is configured to swing and displace around the swing shaft 111 in the ink detection chamber 102. Although the moving member 110 can be moved horizontally, a plurality of guides are required to stabilize this horizontal movement. In this respect, in the present embodiment, the moving member 110 can be stably swung only by the swinging shaft 111, and the movement of the moving member can be stabilized while reducing the number of constituent members.

  Since the moving member 110 was swung, the torsion coil spring 120 was adopted as the biasing means, but the following positive reason was also emphasized as the reason for the adoption. Instead of the torsion coil spring 120, it is also possible to use a compression or tension coil spring. However, in the compression / tensile coil spring, when the displacement amount of the moving member 110 is S and the spring constant is k, the load generated in the spring = k × S, and the load is proportional to the displacement amount S. When a compression or tension coil spring is adopted in this embodiment, the load is maximum in the state shown in FIG. 5, the load is minimum in the state shown in FIG. 6, and the load difference is proportional to the displacement amount of the moving member 110. It becomes a size and cannot be ignored.

On the other hand, the torque generated in the torsion coil spring 120 is not proportional to the displacement amount S of the moving member 110 and is smaller than the load corresponding to the compression or tension coil spring. As an example, the torque M of the torsion coil spring is calculated by M = E · d ⁴ · T / (10.8 × N · D). here,
E = longitudinal elastic modulus kgf / mm ²
d = Wire diameter mm
T = Deflection rate θ / 360 (θ = Deflection angle)
N = total number of turns D = average diameter mm
It is. That is, if the total number of turns N is large to some extent, the deflection angle θ of the present embodiment is not large, so that the difference in torque M between the torsion coil spring 120 of this embodiment and FIG. 5 is small.

  This is advantageous in setting the ink end detection timing in the state of FIG. 6 in consideration of the liquid pressure, the tension of the diaphragm 101, and the torque of the torsion coil spring 120. That is, since the influence of the torque of the torsion coil spring 120 is small in determining the pressure that is the threshold value at which the moving member 110 is displaced in the state of FIG. 6, the accuracy of the threshold value can be increased. Furthermore, even if the positional accuracy of the moving member 110 and the torsion coil spring 120 varies somewhat, variation in torque of the torsion coil spring 120 depending on the position is reduced. Therefore, this embodiment has an effect of reducing deterioration in detection accuracy with respect to variation in dimensional accuracy.

  In addition, since the torsion coil spring 120 can be accommodated in the ink detection chamber 102 and the pressure receiving plate 112 that requires a predetermined pressure receiving area is present, the ink detection chamber 102 has a volume sufficient to accommodate the torsion coil spring 120. Therefore, it is not necessary to increase the volume of the ink detection chamber 102, and the ink detection unit 11 can be kept compact. As a result, the spring that had to be provided outside the ink chamber 102 becomes unnecessary, and the size can be reduced accordingly.

(Modification)
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.

  For example, the time when the pressure receiving plate 112 forms the detection space 134 in cooperation with the ink guiding paths 131, 132, and 133 may be variously changed. In other words, the ink pack 7 is set to a state where the ink in the ink pack 7 is completely exhausted, and the piezoelectric sensor 135 functions as an ink end detection mechanism that detects that the ink remaining amount in the ink pack 7 has become zero. Absent. Instead of this, the time when the pressure receiving plate 112 forms the detection space 134 in cooperation with the ink guiding paths 131, 132, 133 is a state where the ink in the ink pack 7 is almost exhausted (a predetermined small amount remains). It may be set to a state). In this case, the piezoelectric sensor 135 can be used as an ink near-end detection mechanism that detects a state where the ink remaining amount in the ink pack 7 is almost zero.

  Further, in the present invention, the detection space 134 formed in cooperation with one surface of the moving member 110 is not a tubular passage shown in FIGS. 5 and 6 but a simple notch opened to the ink detection chamber 102. You may make it form in a part shape. The cutout portion may be partitioned by one surface of the moving member 110 to form a detection space.

  Furthermore, in the present invention, it is not indispensable to form the first and second flow paths 115 and 116 in the moving member 110, and it is sufficient that the detection space 134 can be partitioned by the moving member 110 in the above embodiment.

  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 110 that is displaced by the liquid pressure, and may be, for example, an optical detection means.

  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 (conductive) 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.

It is a disassembled assembly perspective view of the liquid detection container which concerns on embodiment of this invention. FIG. 2 is an exploded perspective view of the liquid detection device shown in FIG. 1. It is a schematic perspective view which shows the state which accommodated the moving member and the torsion coil spring in the unit main body shown in FIG. It is a schematic perspective view which shows the state which sealed the opening end of the unit main body shown in FIG. 2 with the diaphragm. FIG. 5 is a cross-sectional view of the liquid detection device when the ink pack is full. FIG. 3 is a cross-sectional view of the liquid detection device when not mounted on a cartridge mounting portion of the ink jet recording apparatus and when the ink pack is empty. FIG. 7A is a characteristic diagram showing a residual vibration waveform with a small attenuation, and FIG. 7B is a characteristic diagram showing a residual vibration waveform with a large attenuation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid container (ink cartridge), 3 ... Pressurization chamber, 5 ... Container main body, 7 ... Ink pack (liquid storage part), 7a ... Ink lead-out member, 7b ... Flexible bag, 8 ... Sealing film , 9 ... Ink supply port (liquid supply port), 11 ... Ink detection unit (liquid detection device), 11a ... Connecting needle, 11b ... Ink outlet member, 11c ... Sealing film, 15 ... Flexible film, 17 ... Additive Pressure port, 21 ... Cover, 100 ... Unit main body, 101 ... Diaphragm, 102 ... Ink detection chamber (liquid detection chamber), 103 ... Recess, 104 ... Ink inlet (liquid inlet), 105 ... Ink outlet (liquid) Outlet), 106, 107 ... Bearing portion, 108 ... Step portion, 110 ... Moving member, 111 ... Swing shaft, 112 ... Pressure receiving plate, 113 ... Upstream member, 114 ... Downstream member, 115 ... First flow Road, 116 2nd flow path, 117 ... spring locking part, 120 ... torsion coil spring, 130 ... pressure detection part, 131, 132, 133 ... ink guide path, 134 ... detection space part, 135 ... piezoelectric sensor (piezoelectric detection) means)

Claims (12)

A liquid inlet, a liquid outlet, a flexible diaphragm that is displaced according to a liquid pressure between the liquid inlet and the liquid outlet, and a detector installed so as to face the diaphragm A liquid detection chamber, the volume of which varies according to the liquid pressure,
A moving member provided in the liquid detection chamber;
A detection space provided on the detection portion installation surface, comprising: a detection space communicating with the liquid detection chamber; and a piezoelectric sensor for detecting a residual vibration waveform associated with the vibration by applying vibration to the detection space. And
Have
The moving member has a swing shaft and a pressure receiving plate provided at a position away from the swing shaft,
A part of the moving member is attached to the diaphragm,
The pressure receiving plate is opposed to the detection unit installation surface,
The moving member swings around the swing shaft to displace the pressure receiving plate,
The moving member is biased toward the detection space by a spring,
When the liquid pressure is a predetermined value, the diaphragm expands until the volume of the liquid detection chamber reaches a predetermined volume, and the pressure receiving plate is installed on the detection unit against the urging force of the spring. Away from the surface,
The moving member causes the pressure receiving plate to contact the detection installation surface by the biasing force of the spring when the liquid pressure falls below the predetermined value, and the volume of the liquid detection chamber is set to the predetermined value. Displace the diaphragm to a position that is smaller than the volume,
The liquid sensor according to claim 1, wherein the piezoelectric sensor detects an amplitude value of the residual vibration waveform based on a distance between the piezoelectric sensor and the pressure receiving plate. In claim 1,
In the liquid detection chamber, a recess is formed in which the moving member and the spring are accommodated, and an opening end of the recess is sealed by the diaphragm. In claim 2,
The rocking shaft is formed integrally with the moving member, and the rocking shaft is rotatably supported in the liquid detection chamber. In any one of Claims 1 thru | or 3,
The pressure receiving plate has a first surface facing the detection portion installation surface, and a second surface facing the diaphragm,
The liquid detection device according to claim 1, wherein the diaphragm is fixed to the second surface of the pressure receiving plate. In any one of Claims 1 thru | or 4,
The liquid detection apparatus according to claim 1, wherein the spring is a torsion coil spring. In claim 5,
The torsion coil spring is supported by being inserted through the swing shaft. In claim 5 or 6,
One end side of the swing shaft in the axial direction is fixed to the diaphragm. In claim 7,
The torsion coil spring is inserted into the swing shaft in a range that is biased toward the other end side in the axial direction of the swing shaft. In any one of Claims 1 thru | or 8.
The moving member is
An upstream member extending from the pressure receiving plate toward the liquid inlet side in a direction intersecting the swing axis;
A downstream member extending from the pressure receiving plate toward the liquid outlet along the direction intersecting the swing axis;
Including
The swing shaft is integrally formed in the middle of the upstream portion,
The liquid detection device, wherein a distance from the swing shaft to the free end of the upstream portion is shorter than a distance from the swing shaft to the free end of the downstream portion. In claim 9,
The liquid detection apparatus, wherein the liquid detection chamber includes a guide unit that moves and guides the downstream portion. In claim 9 or 10,
The pressure receiving plate and the upstream portion have a first flow path that guides liquid from the liquid inlet to the detection space,
The pressure detection plate and the downstream portion have a second flow path for guiding the liquid from the detection space to the liquid outlet. A liquid container that discharges the liquid pressurized and stored by the pressurizing means from the liquid outlet;
The liquid detection device according to any one of claims 1 to 11, wherein the liquid discharge port communicates with the liquid inflow port.
A liquid container characterized by comprising:

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