JP2006281550A - Liquid detector, liquid vessel, and manufacturing method for liquid detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely seal a section between components of different materials, free of influence from accuracy. <P>SOLUTION: This liquid ejector comprises a unit base 210 which is made of a resin, a metal sensor base 220 which is housed in a recess 211 of the top surface of the unit base, and a sensor chip 230 which is placed on the top surface of the sensor base. The sensor chip makes an undersurface of a sensor cavity 232 opened, and makes a top surface thereof closed with a diaphragm 233; and a piezoelectric element 234 is arranged on the top surface of the diaphragm. The sensor base and the unit base have an entrance-side channel 222 and an exit-side channel 223, which communicate with the sensor cavity. The sensor chip and the sensor base are fixed to each other by means of an adhesion layer 242 on the top surface of the sensor base and sealed with the adhesion layer 242. The sensor base and the unit base are fixed to each other by means of an adhesive film 240, the inner peripheral side of which is bonded to the top surface of the sensor base via an adhesive layer and the outer peripheral side of which is bonded to a top surface wall 214 around the recess of the unit base, and sealed with the adhesive film 240. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid detection device particularly suitable for detecting a remaining amount of liquid (ink) in a liquid ejecting apparatus such as an ink jet recording apparatus, a liquid container including the same, and a method for manufacturing the liquid detection 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 or a liquid detection device). 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 2001-146024 A

  By the way, when using the sensor unit described in Patent Document 1, it is necessary to allow ink to freely enter the cavity facing the diaphragm, but the side where the piezoelectric element or the like, which is an electrical element, is arranged. Therefore, it is necessary to prevent ink from entering, and therefore, different members must be strictly sealed.

  As a sealing means, there is generally a sealing means such as an O-ring that seals a gap by surface pressure by giving a crushing margin. However, a sealing means such as an O-ring has a sealing performance with a dimensional accuracy of a plurality of parts. Because it depends, there is a problem that stabilization of mass production becomes difficult. In addition, since a separate part for crushing the O-ring or the like is required, there is a problem that the sensor unit (liquid detection device) becomes large.

  In addition, as another sealing means, it is conceivable to seal the gap between parts with an adhesive. However, when using an adhesive, there is a problem that handling is troublesome and it is difficult to stabilize the process in mass production. is there. Especially when making a sensor unit (liquid detection device) by combining multiple parts of different materials (for example, ceramic, metal, resin, etc.) to improve vibration characteristics, it is difficult to select an adhesive. There is also a request to limit the use of adhesive as much as possible.

  In consideration of the above circumstances, the present invention can reliably seal between parts of different materials without being greatly affected by the dimensional accuracy of the parts. An object of the present invention is to provide a liquid detection device that can be stabilized, is space efficient, and can be miniaturized, a liquid container including the liquid detection device, and a method for manufacturing the liquid detection device. And

  The liquid detection device of the present invention is mounted on a resin unit base having a recess on the upper surface, a metal sensor base accommodated in the recess on the upper surface of the unit base, and the upper surface of the sensor base. A sensor chip having a sensor cavity for receiving a liquid to be detected, the lower surface of the sensor cavity being opened to allow the liquid to be received, and the upper surface being a diaphragm The sensor base and the unit base have a liquid storage space that communicates with the sensor cavity, and the sensor chip and the sensor base have a sensor space between the sensor chip and the sensor base. By the adhesive layer arranged on the upper surface of the base, they are fixed to each other and sealed at the same time, and the inner peripheral side is the upper surface of the sensor base between the sensor base and the unit base. Wherein the adhesive film adhered adhesive layer is adhered via and the outer peripheral side to the upper wall around the unit base of the recess, characterized in that it is simultaneously sealed when secured together.

  Further, the present invention is the above-described liquid detection device, wherein the sensor base and the unit base each have an inlet side channel and an outlet side channel with respect to the sensor cavity as the liquid pool space, It is configured to be supplied to the sensor cavity via the inlet-side channel and to be discharged from the sensor cavity via the outlet-side channel.

  Further, the present invention is the above-described liquid detection device, wherein the upper surface of the sensor base protrudes above the recess of the unit base, and the adhesive film is an upper surface wall around the recess of the unit base. It is characterized in that it is bonded to the upper surface of the sensor base at a position higher than the position of bonding to the sensor base.

  The liquid container of the present invention includes a container body having a delivery channel for delivering the liquid stored therein to the outside, and a liquid detection device mounted on the container body so as to be positioned near the end of the delivery channel. The liquid detection device described above is provided as the liquid detection device, and the inlet flow channel, the sensor cavity, and the output flow channel of the liquid detection device are arranged in this order from the upstream side. It is characterized by being interposed in series in the road.

  The method for manufacturing a liquid detection device of the present invention includes a resin unit base having a recess on the upper surface, a metal sensor base housed in the recess on the upper surface of the unit base, and the upper surface of the sensor base. The sensor chip has a sensor cavity for receiving a liquid to be detected, and the lower surface of the sensor cavity is opened to allow reception of the liquid, and the upper surface The sensor chip and the sensor base are fixed to each other and sealed at the same time by an adhesive layer disposed on the upper surface of the sensor base. Between the sensor base and the unit base, the inner peripheral side is bonded to the upper surface of the sensor base via the adhesive layer, and the outer peripheral side is the upper surface wall around the recess of the unit base. A method of manufacturing a liquid detection device that is fixed to each other and sealed by an adhesive film, wherein an adhesive layer is formed on an upper surface of the sensor base, and the sensor chip is placed on the adhesive layer. Then, the sensor chip and the sensor base are integrally fixed and sealed with an adhesive layer, and then the sensor base integrated with the sensor chip is accommodated in a recess in the upper surface of the unit base, and the state By covering the adhesive film from above, the inner peripheral side of the adhesive film is adhered to the upper surface of the sensor base via the adhesive layer, and the outer peripheral side is adhered to the upper surface wall around the recess of the unit base. Thus, the sensor base and the unit base are integrally fixed and sealed with an adhesive film.

  According to the present invention, a sensor base on which a sensor chip is mounted is incorporated into the unit base from above, and in that state, the upper surface and the upper surface of the two parts arranged side by side, that is, the upper surfaces of the sensor base and the unit base are straddled. By simply attaching an adhesive film, it is possible to simultaneously fix and seal between two parts (a metal sensor base and a resin unit base) made of different materials. Therefore, the assembly workability is very good. In addition, since only the adhesive film is pasted over the two parts, the parts can be sealed without being greatly affected by the dimensional accuracy of each part. For example, when the adhesive film is welded by heating and pressurizing with a mass production machine, it is possible to improve the sealing performance just by managing the temperature, pressure and pressure bonding time by the mass production machine, and to stabilize during mass production. be able to. Furthermore, since the adhesive film that affects the sealing performance is easy to mount and space efficient, the sensor unit can be downsized.

  Further, according to the present invention, the sensor base and the unit base are respectively formed with the inlet-side channel and the outlet-side channel with respect to the sensor cavity, and the liquid flows into the sensor cavity via the inlet-side channel. Since the liquid is discharged through the sensor cavity, the liquid flows only in the sensor cavity, and erroneous detection due to the liquid and bubbles remaining in the sensor cavity can be prevented.

  In addition, according to the present invention, the height of the film bonding surface with respect to the unit base is set at a position lower than the height of the film bonding surface with respect to the sensor base, so that the sensor base can be pressed with the adhesive film with a step. In addition, it is possible to enhance the adhesion of the sensor base to the unit base. In addition, mounting without backlash is possible.

  Further, according to the present invention, the liquid detection device is arranged near the end of the delivery flow channel of the container body, and the inlet flow channel, the sensor cavity, and the outlet flow channel of the liquid detection device are arranged in this order from the upstream side. In addition, since it is interposed in series in the delivery channel, the amount of remaining liquid in the container body can be detected accurately.

  In addition, according to the present invention, the sensor base on which the sensor chip is mounted is incorporated into the unit base from above, and in this state, the upper surface and the upper surface of the two parts arranged side by side, that is, both the upper surfaces of the sensor base and the unit base By simply sticking the adhesive film across the two, it is possible to simultaneously fix and seal between two parts (metal sensor base and resin unit base) made of different materials. Therefore, the assembly workability is very good.

  Hereinafter, a liquid detection device according to an embodiment of the present invention and an ink cartridge (liquid container) including the liquid detection device 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 for protecting an ink delivery port (not shown) is attached to the lower end surface of the ink delivery unit 103.

  A sensor housing recess 110 for housing the sensor unit 200 is provided on the narrow side surface of the cartridge case 101, and the sensor unit 200 and the spring 300 are housed in the sensor housing recess 110. As will be described later, the spring 300 presses the sensor unit 200 against the sensor receiving wall 120 (see FIG. 6) on the inner bottom of the sensor receiving recess 110 to crush the seal ring 270 (see FIG. 6), thereby crushing the sensor unit 200. The sealing property between the cartridge case 101 and the cartridge case 101 is ensured.

  The sensor housing recess 110 is open on the narrow side surface of the cartridge case 101, and the sensor unit 200 and the spring 300 are inserted through the opening on the side surface. The opening on the side surface of the sensor housing recess 110 is closed from the outside by a sealing cover 400 with a substrate 500 in a state where the sensor unit 200 and the spring 300 are housed inside.

  FIG. 3 is an exploded perspective view showing each configuration of the sensor unit 200, the spring 300, the sealing cover 400, and the substrate 500. 4 is an exploded perspective view of the sensor unit 200, FIG. 5 is an exploded perspective view of the sensor unit 200 viewed from another angle, and FIG. 6 is a longitudinal sectional view of a sensor unit housing portion of the ink cartridge 100. 7 is a cross-sectional view of the main part of the sensor unit 200, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG.

  As shown in FIG. 6, a sensor receiving wall 120 for receiving the lower end of the sensor unit 200 is provided on the inner bottom portion 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 shown, the cartridge case 101 is provided with a delivery channel for delivering the stored ink to the outside. The sensor unit is positioned near the end of the delivery channel (near the ink delivery port). 200 is arranged. 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 are not sealed with a rigid wall but are opened, and the openings are covered with a resin sealing film 105.

  4 and 5, 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 accommodated in the recess 211 on the upper surface of the unit base 210. Sensor base 220, a sensor chip 230 made of ceramic, for example, mounted on the upper surface of the sensor base 220, an adhesive film 240 for fixing the sensor base 220 and the unit base 210, and an upper side of the unit base 210. A pair of terminal plates 250, a plate-like 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. ing.

  Referring to details of each part, the unit base 210 is made of a material such as polyethylene as shown in FIG. 5 and has a recess 211 into which the sensor base 220 fits at the center of the upper surface, and an upper surface around the recess 211. A mounting wall 215 set one step higher than the top wall 214 is provided outside 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. 4, 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. . As the adhesive layer 242, a material having high adhesiveness between the sensor base 220 and the sensor chip 230 is preferable. For example, an olefin film is preferably used.

  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. 6 and 7, 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.

  The adhesive film 240 is preferably a material having high adhesiveness with both the adhesive layer 242 on the sensor base 220 and the unit base 210. A preferable example of the adhesive film 240 is a film in which an ester film and an olefin film are laminated and the olefin film is the bonding side.

  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. Then, in the accommodated state, the spring 300 presses the pressing cover 260 downward as shown in FIG. 6, so that the seal ring 270 provided on the lower surface of the sensor unit 200 is crushed and the sensor receiving in the sensor accommodating recess 110 is collapsed. The wall 120 is pressed against the wall 120, thereby ensuring a sealing property between the sensor unit 200 and the cartridge case 101.

  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 FIG. 3, the sealing cover 400 that closes the side opening of the sensor receiving recess 110 is provided with a recess 402 into which the substrate 500 is fitted on the outer surface of the plate-like main body 401, and the bottom wall of the recess 402 An opening 403 through which the bent piece 254 of each terminal plate 250 is exposed and pins 406 and 407 for positioning the substrate 500 are provided, and the inner surface of the main body 401 is engaged with a predetermined portion in the sensor receiving recess 110. A pawl 405 is provided in a projecting manner, and is attached to the cartridge case 101 in a state where the sensor unit 200 and the spring 300 are housed in the sensor housing recess 110. In this state, by attaching the substrate 500 to the recess 402 of the sealing cover 400, the predetermined contact 501 of the substrate 500 and the terminal plate 250 are brought into contact with each other. The substrate 500 is provided with notches 506 and holes 507 that engage with positioning pins 406 and 407.

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-described 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 and the unit. By simply sticking the adhesive film 240 across both upper surfaces of the 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. . 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.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus (liquid ejecting apparatus) in which an ink cartridge (liquid container) 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 an exploded perspective view of the sensor unit of FIG. 3. It is the disassembled perspective view seen from another angle of the sensor unit of 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 VIII-VIII arrow sectional drawing of FIG.

Explanation of symbols

100 Ink cartridge 101 Cartridge case (container body)
200 Sensor unit (Liquid detection device)
210 unit base 211 recess 212 inlet side channel 213 outlet side channel 214 upper surface wall 220 sensor base 222 inlet side channel 223 outlet side channel 230 sensor chip 232 sensor cavity 233 diaphragm 234 piezoelectric element 240 adhesive film 242 adhesive layer

Claims (5)

A resin unit base having a recess on the upper surface, a metal sensor base housed in the recess on the upper surface of the unit base, and a sensor chip mounted on the upper surface of the sensor base,
The sensor chip has a sensor cavity for receiving a liquid to be detected;
The lower surface of the sensor cavity is open to allow the liquid to be received, the upper surface of the sensor cavity is closed with a diaphragm, and a piezoelectric element is disposed on the upper surface of the diaphragm;
The sensor base and the unit base have a liquid pool space communicating with the sensor cavity,
Between the sensor chip and the sensor base, the sensor chip and the sensor base are fixed to each other by an adhesive layer disposed on the upper surface of the sensor base and simultaneously sealed,
The sensor base and the unit base are fixed to each other by an adhesive film whose inner peripheral side is bonded to the upper surface of the sensor base via the adhesive layer and whose outer peripheral side is bonded to the upper surface wall around the recess of the unit base. And a liquid detecting device sealed at the same time. The liquid detection device according to claim 1,
The sensor base and the unit base each have an inlet-side channel and an outlet-side channel with respect to the sensor cavity as the liquid storage space, and the liquid is supplied to the sensor cavity via the inlet-side channel. A liquid detection apparatus configured to be discharged from the sensor cavity through an outlet-side flow path. The liquid detection device according to claim 1 or 2,
The upper surface of the sensor base protrudes above the recess of the unit base, and the adhesive film is bonded to the upper surface of the sensor base at a position higher than the bonding position with respect to the upper surface wall around the recess of the unit base. A liquid detection device characterized by comprising: A container body having a delivery flow path for delivering the liquid stored inside to the outside;
The liquid detection device according to any one of claims 1 to 3, wherein the liquid detection device is attached to the container body near the end of the delivery flow path,
A liquid container, wherein an inlet channel, a sensor cavity, and an outlet channel of the liquid detection device are interposed in series in the delivery channel so that they are arranged in this order from the upstream side. A resin unit base having a recess on the upper surface, a metal sensor base housed in the recess on the upper surface of the unit base, and a sensor chip mounted on the upper surface of the sensor base,
The sensor chip has a sensor cavity for receiving a liquid to be detected;
The lower surface of the sensor cavity is open to allow the liquid to be received, the upper surface of the sensor cavity is closed with a diaphragm, and a piezoelectric element is disposed on the upper surface of the diaphragm;
The sensor base and the unit base have a liquid pool space communicating with the sensor cavity,
Between the sensor chip and the sensor base, the sensor chip and the sensor base are fixed to each other by an adhesive layer disposed on the upper surface of the sensor base and simultaneously sealed,
The sensor base and the unit base are fixed to each other by an adhesive film whose inner peripheral side is bonded to the upper surface of the sensor base via the adhesive layer and whose outer peripheral side is bonded to the upper surface wall around the recess of the unit base. A method of manufacturing a liquid detection device, wherein the liquid detection device is sealed at the same time,
By forming an adhesive layer on the upper surface of the sensor base and placing the sensor chip on the adhesive layer, the sensor chip and the sensor base are integrally fixed and sealed together by the adhesive layer,
Next, the sensor base integrated with the sensor chip is accommodated in a recess on the upper surface of the unit base, and in this state, the adhesive film is covered from above, so that the inner peripheral side of the adhesive film is placed on the sensor base. Adhering to the upper surface via the adhesive layer and adhering the outer peripheral side to the upper surface wall around the recess of the unit base, so that the sensor base and the unit base are integrally fixed and sealed with an adhesive film A method of manufacturing a liquid detection device.

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