JP2006315302A - Container with liquid detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a sensor unit to prevent fine matter such as an ink mist from sticking and permit easy electrical connection to the sensor unit from the outside. <P>SOLUTION: The container comprises a cartridge case 101, a sensor storage concave portion 110 provided close to the termination of an ink delivery channel and having an opening 110h for insertion on the narrow side of the cartridge case, a sensor unit 200 stored in the interior of the sensor storage concave portion and detecting the remaining quantity of the ink by using vibration generated by a piezoelectric element, and a lid body 150 to seal the sensor storage concave portion with the sensor unit stored. A contact 501A continuous with sensor unit 200 side terminals 250 in a state of sealing is provided on the outside of the lid body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a container having a liquid detection function (mainly an ink remaining amount detection function) applied to a liquid ejecting apparatus such as an ink jet recording apparatus.

  A typical example of a conventional liquid ejecting apparatus is an ink jet recording apparatus provided with an ink jet recording head for image recording. Other liquid ejecting apparatuses include, for example, an electrode material (conductive paste) used for electrode formation such as an apparatus provided with 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). ) An apparatus equipped with an ejection head, an apparatus equipped with a bioorganic matter ejection head used for biochip production, an apparatus equipped with a sample ejection head as a precision pipette, and the like.

  In an ink jet recording apparatus which is a typical example of a liquid ejecting apparatus, an ink jet recording head having a pressure generating means for pressurizing a pressure generating chamber and a nozzle opening for ejecting pressurized ink as ink droplets is mounted on a carriage. The ink in the ink container is continuously supplied to the recording head via the flow path, so that printing can be continued. The ink container is configured as a detachable cartridge that can be easily replaced by the user when the ink is consumed, for example.

  Conventionally, the ink consumption management method of the ink cartridge includes a method of managing the ink consumption by calculating the number of ink droplets ejected from the recording head and the amount of ink sucked by the maintenance by software, or an ink cartridge. There is a method of managing a point in time when a predetermined amount of ink is actually consumed by attaching an electrode for detecting a liquid level.

  However, the method of managing the ink consumption by calculating the number of ink droplet ejections and the amount of ink by software has the following problems. Some heads have variations in weight of ejected ink droplets. Although the weight variation of the ink droplets does not affect the image quality, the ink cartridge is filled with an amount of ink with a margin in consideration of the accumulation of errors in the ink consumption due to the variation. Therefore, depending on the individual, there is a problem that ink is left by the margin.

  On the other hand, the method for managing the point in time when ink is consumed by the electrode can detect the actual amount of ink, so the remaining amount of ink can be managed with high reliability. However, since the detection of the ink level depends on the conductivity of the ink, there are disadvantages that the types of ink that can be detected are limited and the electrode sealing structure is complicated. In addition, as a material for the electrode, a noble metal having high conductivity and high corrosion resistance is usually used, which increases the manufacturing cost of the ink cartridge. Furthermore, since it is necessary to mount two electrodes, the number of manufacturing steps increases, resulting in an increase in manufacturing cost.

Therefore, an apparatus developed to solve the above problem is disclosed in Patent Document 1 as a piezoelectric device (herein referred to as a sensor unit). This sensor unit is caused by residual vibration (free vibration) of the vibration plate after forced vibration in the presence or absence of ink in the cavity facing the vibration plate on which the piezoelectric elements are stacked. The remaining amount of ink in the ink cartridge is monitored by utilizing the change in the resonance frequency of the residual vibration signal.
JP 2001-146030 A

  By the way, when the above sensor unit is used by being mounted on a liquid container, the piezoelectric element which is a main element that determines the performance of the sensor must be strictly protected. In this regard, although the technique disclosed in Patent Document 1 employs a structure in which an external force is not directly applied to the portion where the piezoelectric element is provided, very fine ink droplets are applied to the print medium as in a recent inkjet printer. When applied to the jetting type, there is a possibility of causing a problem from another viewpoint.

  That is, since a recent ink jet printer is a system that ejects very fine ink droplets, a very small ink mist may float in the printer casing, and this ink mist contains a sensor unit. When entering the portion, for example, ink mist may adhere to the piezoelectric element, which may cause electrostatic breakdown of the piezoelectric element. Since the sensor unit needs to be electrically connected from the outside, simply sealing the sensor unit from the relationship did not solve the problem.

  In consideration of the above circumstances, the present invention can protect the sensor unit from the adhesion of fine substances such as ink mist, and can be easily electrically connected to the sensor unit from the outside. An object of the present invention is to provide a container having a liquid detection function.

(1) A container body having a liquid storage portion inside and a delivery passage for sending the stored liquid to the outside;
A sensor receiving recess provided in the container body, positioned near the end of the delivery passage, and having an insertion opening on the outer surface of the container body;
A sensor unit that is housed in a sensor housing recess through the insertion opening and detects liquid in the container body using vibrations generated by a piezoelectric element;
And a lid that seals the insertion opening of the sensor housing recess in a state in which the sensor unit is housed.
(2) The container according to (1),
A container characterized in that a contact point that is electrically connected to a terminal on the sensor unit side in a state where the insertion opening is sealed is provided on the outer surface of the lid.
(3) A container having the liquid detection function according to (2),
At least a part of the lid is formed of a circuit board provided with an electronic circuit, and an inner contact that is in contact with the terminal on the sensor unit side is provided on the inner surface of the circuit board, and the outer surface of the circuit board Further, an outer contact is provided for direct connection with the inner contact or through the electronic circuit and for electrical connection with an external device.
(4) The container according to (3),
A sealing cover sized to seal the insertion opening of the sensor housing recess, and the circuit board formed separately from the sealing cover and fitted and fixed inside the sealing cover; A container characterized by being configured.
(5) The container according to any one of (1) to (4),
A buffer chamber provided in the container body, adjacent to the sensor receiving recess through a sensor receiving wall, and in series with the delivery passage by communicating with the upstream side and the downstream side of the delivery passage;
An annular sealing member having elasticity for sealing between the sensor unit and the sensor receiving wall;
The sensor unit is housed together with the sensor unit in the sensor housing recess, and by pressing the sensor unit toward the sensor receiving wall, while crushing the seal member, between the seal member and the sensor unit and the sensor receiving wall, A pressing spring that applies a surface pressure necessary for sealing, and
The sensor unit is
A sensor cavity for receiving the liquid to be detected; and the lower surface of the sensor cavity is opened to allow the liquid to be received, the upper surface is closed with a diaphragm, and the piezoelectric element is placed on the upper surface of the diaphragm. A sensor chip having a configuration arranged,
A metal sensor base for mounting and fixing the sensor chip;
The sensor base is mounted and fixed, and has a resin unit base whose bottom surface faces the sensor receiving wall via the seal member when the sensor unit is mounted in the sensor housing portion. ,
The sensor base and the unit base are formed with a liquid pool space communicating with the sensor cavity, and the sensor receiving wall includes the liquid pool space and the buffer chamber inside the annular seal member. A container characterized in that a communication channel is provided.
(6) The container according to (5),
The pressing spring is constituted by a cylindrical compression coil spring, a semi-cylindrical spring support portion for supporting the outer peripheral surface of the pressing spring from the side on the inner surface of the lid, and the pressing spring from both sides. A container characterized in that a pair of engagement arms are formed to be sandwiched and engage the lid body with the container body.
(7) The container according to (5) or (6),
The container body includes a substantially rectangular parallelepiped cartridge case having a pair of wide side surfaces, a pair of narrow side surfaces, a top surface, and a bottom surface, and having a liquid discharge port at a part of the bottom surface. An insertion opening is provided on one narrow side surface of the pair of narrow side surfaces, and the pressing spring and the sensor unit are accommodated in the sensor accommodating recess side by side in a direction perpendicular to the top surface and the bottom surface. A container characterized by being.
(8) The container according to (5) or (6),
The container body includes a substantially rectangular parallelepiped cartridge case having a pair of wide side surfaces, a pair of narrow side surfaces, a top surface, and a bottom surface, and having a liquid discharge port at a part of the bottom surface. An insertion opening is provided on one narrow side surface of the pair of narrow side surfaces, and the pressing spring and the sensor unit are housed in the sensor housing recess side by side in a direction orthogonal to the wide side surface. A container having a liquid detection function characterized by
(9) The container according to any one of (1) to (8),
The container is an ink cartridge of an inkjet printer;
The container, wherein the sensor unit detects a remaining amount of ink.

  According to the present invention, since the sensor housing recess for housing the sensor unit is reliably sealed with the lid, the inside sensor unit can be protected, and the reliability and safety can be improved. In particular, since it is possible to prevent the ink mist (liquid mist) from entering the sensor housing recess by the lid, it is possible to eliminate the possibility of the ink mist adhering to the piezoelectric element. Moreover, since no external airflow enters the sensor housing recess, the liquid can be detected without being affected by the turbulence of the airflow. In addition, even if the container is dropped, the sensor unit can be prevented from being directly impacted, so that the peripheral structure of the delicate piezoelectric element can be protected. In addition, since the contact point that is electrically connected to the terminal on the sensor unit side is provided on the outer surface of the lid, electrical connection can be easily made between the sensor unit and the outside via this contact point.

  In addition, according to the present invention, since at least a part of the lid is configured by the circuit board, the sensor unit and the outside can be easily electrically connected only by providing a contact point on the circuit board. In addition, since it is possible to easily mount an appropriate electronic component such as a memory on the circuit board, it is possible to record information about the container, information about the content liquid, and the like.

  In addition, according to the present invention, the circuit board can be attached to the sealing cover later, so that the sealing cover is a common component, and only the circuit board is an individual component that can be replaced according to the specifications. it can.

  Further, according to the present invention, for example, liquid consumption can be detected by the following principle. That is, when the liquid is consumed, the stored liquid passes through the buffer chamber and is sent to the outside via the sensor cavity of the sensor unit. At this time, the sensor cavity is filled with the liquid when the liquid remains sufficiently in the container body. On the other hand, when the remaining amount of liquid decreases, there is no liquid in the sensor cavity. Therefore, the sensor unit detects a difference in acoustic impedance caused by the change in this state. As a result, it is possible to detect whether there is a sufficient amount of liquid remaining, or whether a certain amount of liquid has been consumed and the remaining amount has been reduced.

  Specifically, when a voltage is applied to the piezoelectric element, the diaphragm is deformed along with the deformation of the piezoelectric element. When the application of voltage is canceled after forcibly deforming the piezoelectric element, flexural vibration remains on the diaphragm for a while. This residual vibration is free vibration between the diaphragm and the medium in the sensor cavity. Accordingly, by setting the voltage applied to the piezoelectric element to a pulse waveform or a rectangular wave, the resonance state between the diaphragm and the medium after the voltage is applied can be easily obtained. This residual vibration is vibration of the diaphragm, and is accompanied by deformation of the piezoelectric element. For this reason, the piezoelectric element generates a counter electromotive force with the residual vibration. By detecting this counter electromotive force externally, the consumption of the liquid can be known.

  In addition, according to the present invention, the pressing spring can be supported by the spring support portion and the engaging arm provided on the inner surface of the lid, so that the pressing spring can be prevented from being displaced and the pressing spring can be assembled. It will be easy.

  Further, according to the present invention, since the pressing spring and the sensor unit are arranged side by side in the height direction of the rectangular parallelepiped cartridge case (direction perpendicular to the top surface and the bottom surface), the reaction force of the pressing spring is increased by the height of the cartridge case. Can be received on the direction wall. Since the cartridge case usually has a large size in the height direction, even when the spring force of the pressing spring is increased, the force of the pressing spring can be received with a sufficient strength. In addition, an opening for insertion of the sensor receiving recess is provided on the narrow side surface of the cartridge case, and a lid having a contact point on the outer surface is arranged there, so that the electrical connection with the outside is performed by the contact point existing on the narrow side surface. Therefore, when a large number of cartridge cases are arranged compactly with the wide side surfaces next to each other, the contacts on the narrow side surfaces of each cartridge case can all be arranged so as to face the outside. Connection can be made easily.

  In addition, according to the present invention, since the pressing spring and the sensor unit are assembled side by side in the thickness direction of the rectangular parallelepiped cartridge case (direction orthogonal to the wide side surface), depending on the dimension obtained by adding the sensor unit and the pressing spring, The thickness of the cartridge case can be reduced. In addition, an opening for insertion of the sensor receiving recess is provided on the narrow side surface of the cartridge case, and a lid having a contact point on the outer surface is arranged there, so that the electrical connection with the outside is performed by the contact point existing on the narrow side surface. Therefore, when a large number of cartridge cases are arranged compactly with the wide side surfaces next to each other, the contacts on the narrow side surfaces of each cartridge case can all be arranged so as to face the outside. Connection can be made easily.

  In addition, according to the present invention, since it is configured as an ink cartridge for an ink jet printer, problems due to ink mist can be solved, and reliability and safety can be improved.

  Hereinafter, an ink cartridge with a liquid detection function (a container having a liquid detection function) according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of an ink jet recording apparatus (liquid ejecting apparatus) in which the ink cartridge of this embodiment is used. In FIG. 1, reference numeral 1 denotes a carriage. The carriage 1 is guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2 and is reciprocated in the axial direction of the platen 5. ing.

  An ink jet recording head 12 is mounted on the side of the carriage 1 that faces the recording paper 6, and an ink cartridge 100 that supplies ink to the recording head 12 is detachably mounted thereon.

  A cap member 13 is disposed at a home position (right side in the figure) which is a non-printing area of the recording apparatus. When the recording head 12 mounted on the carriage 1 is moved to the home position, the cap member 13 is The recording head 12 is pressed against the nozzle forming surface to form a sealed space with the nozzle forming surface. A pump unit 10 is disposed below the cap member 13 for applying a negative pressure to the sealed space formed by the cap member 13 to perform cleaning or the like.

  Further, in the vicinity of the printing area side of the cap member 13, a wiping means 11 having an elastic plate such as rubber is disposed so as to be able to advance and retreat in the horizontal direction with respect to the movement locus of the recording head 12. Is configured to be able to wipe off the nozzle forming surface of the recording head 12 as necessary when reciprocating toward the cap member 13 side.

  FIG. 2 is a perspective view illustrating a schematic configuration of the ink cartridge 100. The ink cartridge 100 incorporates a sensor unit 200 that is a liquid detection device of the present embodiment.

  The ink cartridge 100 includes a resin cartridge case (container body) 101 having an ink storage portion therein, and a resin cover 102 mounted so as to cover the lower end surface of the cartridge case 101. The cover 102 is provided for protecting various sealing films attached to the lower end surface of the cartridge case 101. An ink delivery unit 103 projects from the lower end surface of the cartridge case 101, and a cover film 104 is attached to the lower end surface of the ink delivery unit 103 to protect the ink delivery port (liquid outlet, not shown). ing.

  The cartridge case 101 has a pair of wide side surfaces 101a, a pair of narrow side surfaces 101b, a top surface 101c, and a bottom surface 101d, and has a thin (depth) rectangular parallelepiped shape. A sensor accommodating recess 110 for accommodating the sensor unit 200 is provided in the lower part on the narrow side surface 101b side, and the sensor unit 200 and a spring (pressing spring) 300 are accommodated in the sensor accommodating recess 110. ing.

  As will be described later, the spring 300 presses the sensor unit 200 against the sensor receiving wall 120 (see FIG. 7) at the inner bottom of the sensor housing recess 110 to crush the seal ring 270, thereby The sealing property between the two is ensured.

  A cylindrical compression coil spring is used as the spring 300 in this case, and the spring 300 and the sensor unit 200 are in a direction orthogonal to the top surface 101c and the bottom surface 101d of the cartridge case 101, that is, the cartridge case 101. The sensor units 200 are accommodated in the sensor accommodating recess 110 in the height direction, with the sensor unit 200 positioned above the sensor receiving wall 120 and the spring 300 positioned further above.

  The sensor housing recess 110 has an insertion opening in the narrow side surface 1b of the cartridge case 101, and the sensor unit 200 and the spring 300 are inserted through the insertion opening. The insertion opening of the sensor housing recess 110 is sealed with a lid 150 from the outside in a state where the sensor unit 200 and the spring 300 are housed inside. As will be described in detail later, the lid 150 is formed separately from the sealing cover 400 sized to seal the insertion opening of the sensor housing recess 110 and the sealing cover 400, and is provided inside the sealing cover 400. The circuit board 500 is fitted and fixed.

  3 and 4 are exploded perspective views showing the configurations of the sensor unit 200, the spring 300, the sealing cover 400, and the circuit board 500. FIG. 5 is an exploded perspective view of the sensor unit 200, FIG. 6 is an exploded perspective view of the sensor unit 200 viewed from another angle, and FIG. 7 is a longitudinal sectional view of a sensor unit housing portion of the ink cartridge 100. 8 is a cross-sectional view of the main part of the sensor unit 200, and FIG. 9 is a cross-sectional view taken along the arrow IX-IX in FIG.

  As shown in FIG. 7, a sensor receiving wall 120 for receiving the lower end of the sensor unit 200 is provided on the inner bottom of the sensor housing recess 110 of the cartridge case 101. The sensor receiving wall 120 is a portion where the sensor unit 200 is placed on the upper surface and the seal ring 270 at the lower end of the sensor unit 200 is pressed by the elastic force of the spring 300.

  Below the sensor receiving wall 120, a pair of upstream and downstream sensor buffer chambers 122, 123 separated from each other with a partition wall 127 interposed therebetween are provided. The sensor receiving wall 120 includes a sensor buffer chamber 122, A pair of communication ports 132 and 133 are provided correspondingly to 123.

  Although not particularly shown, the cartridge case 101 is provided with a delivery path for delivering the stored ink to the outside, and is located near the end of the delivery path (in the vicinity of the ink delivery port) so as to be located in the sensor housing recess 110. Is provided, and the sensor unit 200 is disposed in the sensor housing recess 110. In this case, the upstream sensor buffer chamber 122 communicates with the upstream delivery passage via the communication hole 124, and the downstream sensor buffer chamber 123 communicates with the downstream delivery near the ink delivery port via the communication hole 125. It is in communication with the passage.

  The lower surfaces of the sensor buffer chambers 122 and 123 may be sealed with a rigid wall. However, in this embodiment, the sensor buffer chambers 122 and 123 are open, and the openings are covered with a thin sealing film 105 made of resin.

  As shown in FIGS. 5 and 6, the sensor unit 200 is made of a resin-made plate-like unit base 210 having a recess 211 on the upper surface, and a metal plate received in the recess 211 on the upper surface of the unit base 210. Sensor base 220, sensor chip 230 placed and fixed on the upper surface of sensor base 220, adhesive film 240 for fixing sensor base 220 and unit base 210, and a pair of terminals arranged on the upper side of unit base 210 The plate 250, a plate-shaped pressing cover 260 that holds the terminal plate 250 and protects the sensor chip 230, and a rubber seal ring 270 disposed on the lower surface of the unit base 210 are configured.

  Referring to details of each component, the unit base 210 has a recess 211 into which the sensor base 220 fits in the center of the upper surface as shown in FIG. 6, and an upper surface on the outer side of the upper surface wall 214 around the recess 211. The mounting wall 215 is set one step higher than the wall 214. A pair of mounting walls 215 are provided so as to face each other across the recess 211, and four support pins 216 are erected on the four corners of the upper surface of the unit base 210 so as to be positioned on the mounting wall 215. In addition, the bottom wall of the recess 211 is provided with an inlet-side channel 212 and an outlet-side channel 213 (liquid reservoir space) that are circular through holes. Further, as shown in FIG. 5, an oval convex portion 217 into which the seal ring 217 is fitted is provided on the lower surface of the unit base 210, and the inlet-side channel 212 and the outlet-side channel 213 are arranged on the convex portion 217. Is located. The seal ring 217 is made of rubber ring packing and has an annular convex portion 271 having a semicircular cross section on the lower surface.

  The sensor base 220 is made of a metal plate made of stainless steel or the like having higher rigidity than resin for the purpose of improving the acoustic characteristics of the sensor. The sensor base 220 has a rectangular plate shape with four corners chamfered, and corresponds to the inlet-side channel 212 and the outlet-side channel 213 of the unit base 210. It has a flow path 223 (liquid pool space).

  An adhesive layer 242 is formed on the upper surface of the sensor base 220 by, for example, attaching a double-sided adhesive film or applying an adhesive, and the sensor chip 230 is mounted and fixed on the adhesive layer 242. .

  The sensor chip 230 has a sensor cavity 232 that receives ink (liquid) to be detected. The lower surface of the sensor cavity 232 is opened to enable ink reception, and the upper surface is closed with a diaphragm 233. The piezoelectric element 234 is arranged on the upper surface of the diaphragm 233.

  Specifically, as shown in FIGS. 7 and 8, the sensor chip 230 is laminated on a ceramic chip body 231 having a sensor cavity 232 having a circular opening as a center, and an upper surface of the chip body 231. The diaphragm 233 constituting the bottom wall of the cavity 232, the piezoelectric element 234 laminated on the diaphragm 233, and terminals 235 and 236 laminated on the chip body 231.

  Although not specifically shown, the piezoelectric element 234 includes an upper and lower electrode layer connected to each of the terminals 235 and 236, and a piezoelectric layer stacked between the upper and lower electrode layers. It fulfills the function of determining the ink end based on the difference in electrical characteristics depending on the presence or absence of ink in the cavity 232. 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 230 is integrally fixed to the sensor base 220 by the adhesive layer 242 by placing the lower surface of the chip main body 231 on the center of the upper surface of the sensor base 220, and simultaneously with the sensor base 220 by the adhesive layer 242. A space between the sensor chips 230 is sealed. The inlet-side channels 222 and 212 and the outlet-side channels 223 and 213 (liquid pool spaces) of the sensor base 220 and the unit base 210 communicate with the sensor cavity 232 of the sensor chip 230. With this configuration, the ink enters the sensor cavity 232 through the inlet-side channels 212 and 222 and is discharged from the sensor cavity 232 through the outlet-side channels 223 and 213.

  Thus, the metal sensor base 220 on which the sensor chip 230 is mounted is accommodated in the recess 211 on the upper surface of the unit base 210. The sensor base 220 and the unit base 210 are integrally bonded by covering the resin adhesive film 240 thereon.

  That is, the adhesive film 240 has an opening 241 at the center, and the sensor base 220 is covered from the recess 211 on the upper surface of the unit base 210 so as to cover the sensor base 220 from the center opening 241 to the sensor chip 230. Is exposed. Further, by bonding the inner peripheral side of the adhesive film 240 to the upper surface of the sensor base 220 via the adhesive layer 242 and bonding the outer peripheral side to the upper surface wall 214 around the recess 211 of the unit base 210, That is, by sticking the adhesive film 240 across the upper surfaces of the two components (the sensor base 220 and the unit base 210), the sensor base 220 and the unit base 210 are fixed to each other and sealed at the same time.

  In this case, the upper surface of the sensor base 220 protrudes above the recess 211 of the unit base 210, and the adhesive film 240 is at a position higher than the bonding position with respect to the upper wall 214 around the recess 211 of the unit base 210. The sensor base 220 is bonded to the upper surface. Thus, by setting the height of the film bonding surface with respect to the sensor base 220 to a position higher than the height of the film bonding surface with respect to the unit base 210, the sensor base 220 can be pressed with the adhesive film 240 with a step. In addition, the fixing force of the sensor base 220 to the unit base 210 can be enhanced. In addition, mounting without backlash is possible.

  Each terminal plate 250 includes a strip-shaped substrate portion 251, spring pieces 252 projecting from the side edge of the substrate portion 251, attachment holes 253 formed on both sides of the substrate portion 251, and both ends of the substrate portion 251. And are arranged on the upper surface of the mounting wall 215 of the unit base 210 in a state of being positioned through the support pins 216 in the mounting holes 253, respectively. Then, by placing the pressing cover 260 from above, it is sandwiched between the unit base 210 and the pressing cover 260, and in this state, each spring piece 252 is brought into contact with the terminals 235 and 236 on the upper surface of the sensor chip 230. Yes.

  The holding cover 260 is disposed on the upper surface of the mounting wall 215 of the unit base 210 while sandwiching the board portion 251 of the terminal plate 250, and is disposed at the four corners of the flat plate portion 261, and fits on the support pins 216 of the unit base 210. Four mounting holes 262, a standing wall 263 provided on the central upper surface of the flat plate portion 261, a spring receiving seat 264 provided on the standing wall 263, a lower surface of the flat plate portion 261, and a spring piece 252 of the terminal plate 250 The sensor plate 220 and the sensor chip 230 accommodated in the recess 211 on the upper surface of the unit base 210 are mounted on the upper surface of the unit base 210 while pressing the terminal plate 250 from above. Is protecting.

  In order to assemble the sensor unit 200 with the above components, first, the adhesive layer 242 is formed on the entire upper surface of the sensor base 220, and the sensor chip 230 is placed on the adhesive layer 242. The bases 220 are integrally fixed and sealed with an adhesive layer 242.

  Next, the sensor base 220 integrated with the sensor chip 230 is accommodated in the recess 211 on the upper surface of the unit base 210, and in this state, the adhesive film 240 is covered from above, so that the inner peripheral side of the adhesive film 240 is covered. Is bonded to the upper surface of the sensor base 220 via the adhesive layer 242, and the outer peripheral side is bonded to the upper surface wall 214 around the recess 211 of the unit base 210. Accordingly, the sensor base 220 and the unit base 210 can be integrally fixed and sealed with the adhesive film 240.

  Next, the terminal plate 250 is disposed on the unit base 210 while fitting the mounting holes 253 to the support pins 216 of the unit base 210, and the pressing cover 260 is disposed thereon. Further, at an arbitrary stage, the seal ring 270 is fitted on the convex portion 217 on the lower surface of the unit base 210. As described above, the sensor unit 200 can be assembled.

  The sensor unit 200 is configured as described above, and is housed together with the spring 300 in the sensor housing recess 110 of the cartridge case 100. In the accommodated state, as shown in FIG. 7, the spring 300 presses the holding cover 260 downward, and the seal ring 270 provided on the lower surface of the sensor unit 200 is crushed. The sensor receiving wall 120 is press-contacted, and thereby the sealing property between the sensor unit 200 and the cartridge case 101 is ensured.

  As a result of such assembly, the upstream buffer chamber 122 in the cartridge case 101 enters the sensor unit 200 through the communication hole 132 of the sensor receiving wall 120 under a condition in which sealing performance is ensured. The downstream buffer chamber 123 in the cartridge case 101 is communicated with the outlet channels 213 and 223 in the sensor unit 200 through the communication hole 133 of the sensor receiving wall 120. The inlet-side channels 212 and 222, the sensor cavity 232, and the outlet-side channels 213 and 223 are interposed in series in the delivery channel in the cartridge case 101 so that they are arranged in this order from the upstream side.

  Here, the upstream flow path connected to the sensor cavity 232 includes the upstream buffer chamber 122 having a large cross section, the communication port 132, and the input flow paths 212 and 222 in the sensor unit 200 having a small flow section. An upstream narrow channel). Further, the downstream flow path connected to the sensor cavity 232 includes the downstream buffer chamber 123 having a large flow section, the communication port 133, and the output flow paths 213 and 223 (downstream) in the sensor unit 200 having a small flow section. Side narrow channel).

  Further, as shown in FIGS. 3 and 4, the sealing cover 400 that closes the side opening of the sensor housing recess 110 is provided with a recess 402 into which the circuit board 500 is fitted on the outer surface of the plate-like cover body 401. Two openings 403 where the bent pieces 254 of the terminal plates 250 are exposed and pins 406 and 407 for positioning the circuit board 500 are provided on the bottom wall of the terminal plate 250, and the spring 300 is provided on the inner surface of the cover body 401. A cylindrical surface-shaped spring support portion 409 that supports the outer peripheral surface from the side and a pair of engagement arms 405 that are locked to a predetermined portion in the sensor housing recess 110 are provided. The pair of engagement arms 405 are provided at positions that sandwich the spring 300 from both the left and right sides. Further, the sealing cover 400 is provided with positioning holes 411 and 412 that fit into a pair of upper and lower positioning pins 101p and 101b protruding from the peripheral wall of the sensor housing recess 110.

  In addition, the circuit board 500 has contacts 501A and 501B formed on the outer surface and the inner surface of the insulating substrate 501 that is just sized to fit into the concave portion 402 of the cover main body 401, and an electronic component such as a memory as necessary. An electronic circuit (not shown) including the above is formed. The insulating substrate 501 is provided with notches 506 and holes 507 that engage with positioning pins 406 and 407 on the sealing cover 400 side.

  In this case, the inner contact 501B exposed on the inner surface of the circuit board 500 is a contact that makes contact with the bent piece 254 of the terminal plate 250 on the sensor unit 200 side when the sensor housing recess 110 is closed with the lid 150. The outer contact point 501A is directly connected to the inner contact point 501B or connected through the electronic circuit, and is a contact point for electrical connection with an external device.

  The lid 150 including the sealing cover 400 and the circuit board 500 is attached to the cartridge case 101 after the sensor unit 200 and the spring 300 are accommodated in the sensor accommodating recess 110, and in this state, the circuit A contact 501 </ b> A on the outer surface of the substrate 500 is electrically connected to the terminal plate 250.

Next, the principle of ink detection by the sensor unit 200 will be described.
When the ink in the ink cartridge 101 is consumed, the stored ink is sent from the ink delivery unit 103 to the recording head 12 of the ink jet recording apparatus via the sensor cavity 232 of the sensor unit 200.

  At this time, the sensor cavity 232 is filled with ink when ink is sufficiently left in the ink cartridge 100. On the other hand, when the remaining amount of ink in the ink cartridge 100 decreases, no ink exists in the sensor cavity 232.

  Therefore, the sensor unit 200 detects a difference in acoustic impedance caused by the change in this state. Accordingly, it is possible to detect whether the ink is sufficiently remaining or whether the remaining amount is low due to consumption of a certain amount of ink.

  Specifically, when a voltage is applied to the piezoelectric element 234, the diaphragm 233 is deformed along with the deformation of the piezoelectric element 234. When the application of voltage is canceled after the piezoelectric element 234 is forcibly deformed, the flexural vibration remains on the diaphragm 233 for a while. This residual vibration is free vibration between the diaphragm 233 and the medium in the cavity 232. Therefore, by setting the voltage applied to the piezoelectric element 234 to a pulse waveform or a rectangular wave, the resonance state between the diaphragm 233 and the medium after the voltage is applied can be easily obtained.

  This residual vibration is vibration of the diaphragm 233 and is accompanied by deformation of the piezoelectric element 234. For this reason, the piezoelectric element 7 generates a counter electromotive force with the residual vibration. This counter electromotive force is detected externally through the terminal plate 250.

  Since the resonance frequency can be specified by the back electromotive force detected in this way, the presence or absence of ink in the ink cartridge 100 can be detected based on this resonance frequency.

  According to the above embodiment, since the sensor housing recess 110 for housing the sensor unit 200 is securely sealed by the lid 150, the inner sensor unit 200 can be protected, and reliability and safety can be improved. Can be improved. In particular, since the lid 150 can prevent the ink mist (liquid mist) from entering the sensor housing recess 110, the possibility of the ink mist adhering to the piezoelectric element 234 can be eliminated. In addition, since the outside air current does not enter the sensor housing recess 110, the remaining amount of ink can be detected without being affected by the disturbance of the air current.

  Further, even if the ink cartridge 100 is dropped, the sensor unit 200 can be prevented from being directly impacted, so that the delicate piezoelectric element 234 and the surrounding structure can be protected. In addition, since the contact 501A that is electrically connected to the terminal plate 250 on the sensor unit 200 side is provided on the outer surface of the lid 150, electrical connection can be easily performed between the sensor unit 200 and the outside via the contact 501A. Can do.

  In addition, since a part of the lid 150 is configured by the circuit board 500, the sensor unit 200 and the outside can be easily electrically connected only by providing the contacts 501A and 501B on the circuit board 500. In addition, since it is possible to easily mount an appropriate electronic component such as a memory on the circuit board 500, it is possible to record information about the ink cartridge 100, information about the ink, and the like.

  Since the circuit board 500 is manufactured separately from the sealing cover 400 and can be freely attached to the sealing cover 400 later, only the sealing cover 400 is used as a common component, and the circuit board 500 is used as a specification. It can also be arranged as individual parts that can be replaced according to the above.

  In addition, since the spring 300 can be supported by the spring support portion 409 and the engagement arm 405 provided on the inner surface of the sealing cover 400, the spring 300 can be prevented from being displaced and the spring 300 can be easily assembled. become able to.

  In the present embodiment, the spring 300 and the sensor unit 200 are assembled side by side in the height direction of the rectangular parallelepiped cartridge case 101 (the direction perpendicular to the top surface 101c and the bottom surface 101d). It can be received by the wall surface in the height direction of the cartridge case 101 (the upper wall surface of the sensor housing recess 110). Here, since it is normal that the cartridge case 101 has a large dimension in the height direction, even when the spring force of the spring 300 is increased, the force of the spring 300 is increased with sufficient strength in the height direction. The wall surface (the upper wall surface of the sensor housing recess 110) can be received.

  Further, since the insertion opening 110h of the sensor housing recess 110 is provided in the narrow side surface 101b of the cartridge case 101 and the lid 150 having the contact point 501A on the outer surface is disposed there, the contact point 501A existing on the narrow side surface 101b Electrical connection with the outside can be made. Accordingly, when a large number of cartridge cases 101 are arranged compactly with the wide side surfaces 101a next to each other, the contacts 501A on the narrow side surfaces 101b of the cartridge cases 101 can all be arranged so as to face the outside. Can be easily connected.

  In addition, according to the present embodiment, the sensor base 220 on which the sensor chip 230 is mounted is incorporated into the unit base 210 from above, and in this state, the upper surface and the upper surface of the two components arranged side by side, that is, the sensor base 220 By simply sticking the adhesive film 240 across both upper surfaces of the unit base 210, it is possible to simultaneously fix and seal between two parts (metal sensor base 220 and resin unit base 210) made of different materials. it can. Therefore, the assembly workability is very good. In addition, since the adhesive film 240 is only pasted over two parts, the parts can be sealed without being affected by the dimensional accuracy of each part. In addition, for example, when the adhesive film 240 is heated and pressurized by a mass production machine and is welded, the sealing performance can be improved only by controlling the temperature and pressure by the mass production machine, so that stabilization during mass production is achieved. Can do. Furthermore, since the adhesive film 240 that affects the sealing performance is easy to mount and has good space efficiency, the sensor unit 200 can be downsized.

  In addition, the inlet side channels 212 and 222 and the outlet side channels 213 and 223 with respect to the sensor cavity 232 are respectively formed in the sensor base 220 and the unit base 210, and the ink is supplied to the sensor cavity 232 through the inlet side channels 212 and 222. Since the ink flows into the sensor cavity 232 and the liquid or bubbles stay in the sensor cavity 232, the detection error is caused. Can be prevented.

  Further, since the height of the adhesive surface of the adhesive film 240 with respect to the unit base 210 is set at a position lower than the height of the adhesive surface with respect to the sensor base 220, the sensor base 220 is pressed with the adhesive film 240 with a step. Thus, the fixing force of the sensor base 220 to the unit base 210 can be enhanced. In addition, mounting without backlash is possible.

  Further, the sensor unit 200 is arranged near the end of the delivery flow path in the cartridge case 101, and the inlet side flow paths 212 and 222, the sensor cavity 232, and the outlet side flow paths 213 and 223 of the sensor unit 200 are arranged upstream in this order. In other words, the remaining liquid amount in the ink cartridge 100 can be accurately detected.

  In the above embodiment, the sensor receiving wall 120 is provided on the lower side of the sensor housing recess 110, and the two sensor buffer chambers 122 and 123 that open to the lower surface of the cartridge case 101 are provided on the lower side, and the spring 300 and the sensor are provided. The case where the units 200 are arranged vertically and arranged in the sensor receiving recess 110 and the pressure direction of the spring 300 acts downward toward the sensor receiving wall 120 is shown. You may comprise like the ink cartridge 100B.

  That is, the ink cartridge 100B of this embodiment is the same up to the point where the sensor housing recess 110 is provided on the narrow side surface 101b of the cartridge case 101B configured in the same manner as the above embodiment, but the sensor receiving wall is the same. Two sensor buffers 120 are provided not on the lower side of the sensor housing recess 110 but on the side, that is, on the side of the wide side surface 101a, and further open on the wide side surface 101a on the side of the wide side surface 101a of the sensor receiving wall 120. The chambers 122 and 123 are provided, the spring 300 and the sensor unit 200 are arranged in the sensor receiving recess 110 side by side in the left-right direction orthogonal to the wide side surface 101a, and the pressing direction of the spring 300 is directed toward the side sensor receiving wall 120. Are configured to act sideways.

  That is, the sensor buffer chambers 122 and 123 are provided in a direction orthogonal to the case of the above-described embodiment, and the sensor unit 200 and the spring 300 are laterally arranged in accordance therewith. Since the configuration is the same except that the directions are different, the same components are denoted by the same reference numerals and description thereof is omitted. The same applies to the point that the insertion opening 101h of the sensor housing recess 110 is closed with the lid 150 made of the sealing cover 4005 and the circuit board 400.

  As described above, the spring 300 and the sensor unit 200 are arranged side by side in the thickness direction of the rectangular parallelepiped cartridge case 101B (direction orthogonal to the wide side surface 101a), so that the size of the sensor unit 200 and the spring 300 can be adjusted. Thus, the thickness of the cartridge case 101B can be reduced. Other effects are the same as in the above embodiment.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus (liquid ejecting apparatus) in which an ink cartridge according to an embodiment of the present invention is used. 1 is an exploded perspective view illustrating a schematic configuration of an ink cartridge according to an embodiment of the present invention. FIG. 3 is a perspective view showing a detailed configuration of components including a sensor unit (liquid detection device) installed in the ink cartridge of FIG. 2. FIG. 4 is a perspective view showing a detailed configuration of components including a sensor unit (liquid detection device) installed in the ink cartridge of FIG. 2 as seen from another direction. FIG. 5 is an exploded perspective view of the sensor unit of FIGS. 3 and 4. It is the disassembled perspective view seen from another angle of the sensor unit of FIG. 3, FIG. FIG. 3 is a longitudinal sectional view of a portion where a sensor unit of the ink cartridge of FIG. 2 is mounted. It is a principal part expanded sectional view of the sensor unit of FIG. It is IX-IX arrow sectional drawing of FIG. It is a disassembled perspective view which shows schematic structure of the ink cartridge of other embodiment of this invention. FIG. 4 is a front view of a portion where a sensor unit is assembled to an ink cartridge. It is sectional drawing seen from the same direction as FIG.

Explanation of symbols

100, 100B ink cartridge (container with liquid detection function)
101,101B Cartridge case (container body)
101a Wide side surface 101b Narrow side surface 101c Top surface 101d Bottom surface 103 Ink delivery part 110 Sensor accommodating recess (sensor accommodating part)
110h Insertion opening 120 Sensor receiving wall 122 Upstream sensor buffer chamber 123 Downstream sensor buffer chamber 132, 133 Communication hole (flow path)
150 Lid 200 Sensor Unit 210 Unit Base 212 Inlet Channel (Liquid Pool Space)
213 Outlet channel (Liquid pool space)
220 Sensor base 222 Inlet flow path (Liquid pool space)
223 Outlet channel (Liquid pool space)
230 Sensor chip 232 Sensor cavity 233 Vibration plate 234 Piezoelectric element 250 Terminal plate 270 Seal ring (annular seal member)
400 Sealing cover 405 Engagement arm 409 Sensor support 500 Circuit board 501A Outer contact 501B Inner contact

Claims (9)

A container body having a liquid storage portion inside and a delivery passage for delivering the stored liquid to the outside;
A sensor receiving recess provided in the container body, positioned near the end of the delivery passage, and having an insertion opening on the outer surface of the container body;
A sensor unit that is housed in a sensor housing recess through the insertion opening and detects liquid in the container body using vibrations generated by a piezoelectric element;
And a lid that seals the insertion opening of the sensor housing recess in a state in which the sensor unit is housed. The container according to claim 1,
A container characterized in that a contact point that is electrically connected to a terminal on the sensor unit side in a state where the insertion opening is sealed is provided on the outer surface of the lid. A container having the liquid detection function according to claim 2,
At least a part of the lid is formed of a circuit board provided with an electronic circuit, and an inner contact that is in contact with the terminal on the sensor unit side is provided on the inner surface of the circuit board, and the outer surface of the circuit board Further, an outer contact is provided for direct connection with the inner contact or through the electronic circuit and for electrical connection with an external device. A container according to claim 3,
A sealing cover sized to seal the insertion opening of the sensor housing recess, and the circuit board formed separately from the sealing cover and fitted and fixed inside the sealing cover; A container characterized by being configured. The container according to any one of claims 1 to 4,
A buffer chamber provided in the container body, adjacent to the sensor receiving recess through a sensor receiving wall, and in series with the delivery passage by communicating with the upstream side and the downstream side of the delivery passage;
An annular sealing member having elasticity for sealing between the sensor unit and the sensor receiving wall;
The sensor unit is housed together with the sensor unit in the sensor housing recess, and by pressing the sensor unit toward the sensor receiving wall, while crushing the seal member, between the seal member and the sensor unit and the sensor receiving wall, A pressing spring that applies a surface pressure necessary for sealing, and
The sensor unit is
A sensor cavity for receiving the liquid to be detected; and the lower surface of the sensor cavity is opened to allow the liquid to be received, the upper surface is closed with a diaphragm, and the piezoelectric element is placed on the upper surface of the diaphragm. A sensor chip having a configuration arranged,
A metal sensor base for mounting and fixing the sensor chip;
The sensor base is mounted and fixed, and has a resin unit base whose bottom surface faces the sensor receiving wall via the seal member when the sensor unit is mounted in the sensor housing portion. ,
The sensor base and the unit base are formed with a liquid pool space communicating with the sensor cavity, and the sensor receiving wall includes the liquid pool space and the buffer chamber inside the annular seal member. A container characterized in that a communication channel is provided. The container according to claim 5,
The pressing spring is constituted by a cylindrical compression coil spring, a semi-cylindrical spring support portion for supporting the outer peripheral surface of the pressing spring from the side on the inner surface of the lid, and the pressing spring from both sides. A container characterized in that a pair of engagement arms are formed to be sandwiched and engage the lid body with the container body. The container according to claim 5 or 6,
The container body includes a substantially rectangular parallelepiped cartridge case having a pair of wide side surfaces, a pair of narrow side surfaces, a top surface, and a bottom surface, and having a liquid discharge port at a part of the bottom surface. An insertion opening is provided on one narrow side surface of the pair of narrow side surfaces, and the pressing spring and the sensor unit are accommodated in the sensor accommodating recess side by side in a direction perpendicular to the top surface and the bottom surface. A container characterized by being. The container according to claim 5 or 6,
The container body includes a substantially rectangular parallelepiped cartridge case having a pair of wide side surfaces, a pair of narrow side surfaces, a top surface, and a bottom surface, and having a liquid discharge port at a part of the bottom surface. An insertion opening is provided on one narrow side surface of the pair of narrow side surfaces, and the pressing spring and the sensor unit are housed in the sensor housing recess side by side in a direction orthogonal to the wide side surface. A container characterized by. A container according to any one of claims 1 to 8,
The container is an ink cartridge of an inkjet printer;
The container, wherein the sensor unit detects a remaining amount of ink.

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