JP4281477B2 - Liquid cartridge - Google Patents

Description

  The present invention relates to a liquid cartridge that supplies a liquid to a liquid ejecting apparatus.

An ink jet recording apparatus performs recording by ejecting ink from a recording head onto a recording material such as recording paper. Ink ejected by the ink jet recording apparatus is supplied from an ink cartridge.
The ink cartridge communicates with the atmosphere, and receives air therein as ink is supplied to the ink jet recording apparatus. The ink cartridge also includes a liquid level sensor for detecting the liquid level in order to detect the remaining amount of ink. The liquid level sensor has, for example, a piezoelectric vibrating body. Based on the difference in residual vibration between when the piezoelectric vibrating body is in contact with liquid and when it is in contact with air, the liquid level is higher than that of the piezoelectric vibrating body. It is detected whether it exists on top (for example, refer patent document 1).

JP 2001-328278 A

  When the ink cartridge receives air, bubbles may be generated in the ink. When the ink contains a surfactant or the like, bubbles accumulate on the liquid surface. The bubbles move on the liquid level sensor when the liquid level becomes substantially the same as the liquid level sensor. When bubbles are attached to the liquid level sensor, the residual vibration of the piezoelectric vibrator shows the same characteristics as when it is in contact with air, and when the wall portion at the boundary between the bubbles and the bubbles is attached to the liquid sensor, the piezoelectric vibration The residual vibration of the body exhibits the same characteristics as when in contact with ink. For this reason, when bubbles move on the liquid level sensor, the output of the liquid level sensor is not stable, and the liquid level sensor may not be able to accurately detect the liquid level. Therefore, it is necessary to prevent bubbles from adhering to the liquid level sensor or to stably hold the bubbles.

According to the first aspect of the present invention, the liquid cartridge is attached to the liquid ejecting apparatus and supplies the liquid to the liquid ejecting apparatus, and has a bottomed housing shape having an opening on the side surface. A cartridge main body having a liquid storage section for storing, a liquid level sensor for detecting the liquid level of the liquid storage section, and a liquid level sensor for stably holding bubbles attached to the liquid level sensor. A sensor peripheral wall that is enclosed from the side and that opens below the liquid level sensor, a film that seals the opening of the cartridge body, and a circular opening that is provided at a location where the liquid level sensor of the cartridge body is disposed, The liquid level sensor has a piezoelectric vibrating body, detects the liquid level based on residual vibration in the piezoelectric vibrating body, the liquid level sensor and the sensor peripheral wall are arranged on the side surface facing the film, Around the sensor Is arranged to stand from the side surface having the liquid level sensor toward the film, and has a gap between the film and the sensor peripheral wall has a substantially inverted U shape, and has a substantially semicircular upper portion. Each of the upper two lower ends, and a foot portion extending downwardly by approximately the same length as the half of the inner diameter of the upper portion. The inner diameter of the upper portion of the sensor peripheral wall is equal to the inner diameter of the circular opening portion. A liquid cartridge is provided which is small in comparison and approximately equal to the average value of the outer diameter of the bubbles, and the liquid level sensor is located at the center of the semicircle forming the top.
According to this liquid cartridge, since the bubbles attached to the liquid level sensor are stably held by the sensor peripheral wall, they do not move on the liquid level sensor. For this reason, even if the liquid level drops and bubbles formed on the liquid level adhere to the liquid level sensor, the output of the liquid level sensor is stabilized. When the bubble itself adheres, the liquid level sensor can detect that the liquid level has dropped when the bubble has adhered. Further, since the lower part of the sensor peripheral wall is open, the bubbles attached to the liquid level sensor are broken when the liquid level is sufficiently lowered. Therefore, even if a plurality of bubbles enter the sensor peripheral wall and the wall part at the boundary between the bubbles and the bubble adheres to the liquid level sensor, the liquid level sensor indicates that the liquid level has dropped when the bubble is broken. Can be detected. In particular, since the liquid level sensor is disposed at the center of the region surrounded by the sensor peripheral wall, the liquid level sensor can more reliably detect that the liquid level has dropped.

The liquid storage unit may further include an air inlet arranged below the sensor peripheral wall, and the sensor peripheral wall may be arranged at a position different from the air inlet in the horizontal direction.
The sensor peripheral wall may be formed separately from the main body of the liquid cartridge and then joined to the main body. In this way, the main body of the liquid cartridge can be made common by changing the dimensions of the sensor peripheral wall according to the physical properties and composition of the liquid and the structure of the main body of the liquid cartridge.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  FIG. 1 shows an example of a liquid cartridge suitable for supplying a liquid to a liquid ejecting head of a liquid ejecting apparatus, using an ink cartridge 100 for an ink jet recording apparatus as seen from an obliquely upper side. It is a front perspective view.

  The liquid ejecting apparatus referred to in the present invention is not only a liquid ejecting head of an ink jet recording apparatus, but also a colorant ejecting head of a color filter manufacturing apparatus for manufacturing a color filter of a liquid crystal display, an organic EL display, an FED (surface And an electrode material (conductive paste) ejecting head for forming electrodes such as a light emitting display), a bio-organic matter ejecting head of a biochip manufacturing apparatus for manufacturing a biochip, and a sample ejecting head as a precision pipette.

  2 and 3 are rear perspective views of the ink cartridge 100 of FIG. 1 as viewed obliquely from below, and FIG. 2 is a diagram illustrating a state before the film 110 is attached to the surface of the ink cartridge 100. FIG. 4 is a diagram illustrating a state where a film 110 is attached to the ink cartridge 100. 4 and 5 are exploded perspective views showing the members constituting the ink cartridge 100 in an exploded manner. 6 and 7 are front views of the ink cartridge 100 of FIG. 1, FIG. 6 is a diagram showing a state before the film 130 is attached to the opening 122 of the ink cartridge 100, and FIG. 2 is a diagram illustrating a state in which a film is attached to an opening portion of the ink cartridge. FIG. In FIG. 7, the film 130 is attached to the area indicated by hatching.

  As shown in FIG. 4, the ink cartridge 100 includes a bottomed substantially casing-shaped cartridge main body (container main body) 120 having an opening 122, a film 130 covering almost the entire surface of the opening 122, and the film 130. A lid 140 is provided to cover the outside. The interior of the cartridge body 120 is partitioned by ribs and walls as will be described later. The film 130 seals almost the entire surface of the opening 122 of the cartridge main body 120 so that the inside thereof is in a sealed state. The lid 140 is further fixed to the cartridge body 120 so as to cover the outside of the film 130 in an unsealed state.

  The cartridge main body 120 includes an ink storage unit 111 that stores ink, an ink flow path unit from the ink storage unit 111 to the ink supply unit 160, an ink side passage that allows the ink storage unit 111 to communicate with the atmosphere, an atmospheric valve storage unit, And an air communication portion including an air passage, and is integrally formed of, for example, polypropylene (PP).

  The ink cartridge 100 further includes an ink supply control unit 150, an ink supply unit 160, a storage unit 170, and an engagement lever 180. The ink supply unit 160 is disposed on the lower surface of the cartridge main body 120, and an ink supply needle of a holder to which the ink cartridge 100 is mounted is inserted, and the ink stored in the ink storage unit 111 is transferred to the recording head of the ink jet recording apparatus. Supply. The storage unit 170 is caulked to the mounting portion 190, and the mounting portion 190 is caulked below the side surface of the cartridge main body 120. The storage unit 170 stores information on the type of the ink cartridge 100, information on the color of the ink held by the ink cartridge 100, information on the existing amount of ink, and the like. Pass this information between. The engagement lever 180 is formed on the upper portion of the side surface of the cartridge main body 120 that faces the mounting portion 190 and engages with the holder of the ink jet recording apparatus.

  The ink supply control unit 150 supplies ink in the ink storage unit 111 to the ink supply unit 160 due to a pressure difference between the ink storage unit 111 and the ink supply unit 160 that is generated as the ink is consumed. The ink supply control unit 150 is elastically deformable and includes a membrane valve 900 that is an example of a valve member inserted into the differential pressure valve unit housing portion 495 of the cartridge body 120 and a valve lid 151 that covers the differential pressure valve unit housing portion 495. And a coil spring 907 disposed between the membrane valve 900 and the valve lid 151.

As shown in FIGS. 6 and 7, the ink containing portion 111 is largely divided into an upper portion and a lower portion by a wall 272 extending in the horizontal direction, and an air-side containing portion 270 capable of communicating with the atmosphere through a communication hole 242 is provided at the lower portion. In addition, a supply-side storage unit 290 including two first ink storage units 292 and a second ink storage unit 294 that are shielded from the atmosphere is formed in the upper part. The supply-side container 290 is divided into two parts, a first ink container 292 and a second ink container 294, by an oblique wall 271 having a communication part 276 in the vicinity (lower region) of the wall 272, and the second ink. A flow path portion 296 is formed so as to be surrounded by the accommodating portion 294. The flow path portion 296 is connected to the second ink storage portion 294 via the lower communication portion 278 and is connected to the ink supply control means 150 via the passages 298 and 300 and the through hole 918.
The downstream side of the ink supply control means 150 is formed at one end of a communication hole 910 communicating with the ink supply control means 150, a communication portion 302 communicating with the communication hole 910, a flow path 321, and a flow path 321. It is configured to communicate with the ink supply unit 160 through a through hole 323 formed toward the end and a communication unit 304 having one end communicating with the through hole 323.

  The atmosphere-side container 270 and the first ink container 292 are communicated with each other by a communication path 295 extending vertically, and the ink in the atmosphere-side container 270 is supplied to the first ink corresponding to the consumption of ink from the ink supply unit 160. The ink is sucked into the storage portion 292 and then flows into the ink supply control means 150 through the second ink storage portion 294, the flow path portion 296, and the like. From the atmosphere side container 270 of the ink container 111 to the ink supply control means 150, the communication part 274, the second ink injection port 162, the communication path 295, the communication parts 276 and 278, the flow path part 296, and the paths 298 and 300. The ink flows through the through holes 918 in this order.

  On the other hand, the atmospheric valve portion 250 has a hollow portion 232 that is an atmospheric valve accommodating portion in which the atmospheric valve 254 is accommodated, and a wall surface below the hollow portion 232 has a diameter slightly larger than the diameter of the shaft portion 264 of the atmospheric valve 254. Has a communication hole 239 that also serves as an air communication channel, and the shaft portion 264 of the air valve 254 is constantly urged toward the bottom surface of the ink cartridge 100 by a spring 255 and is slidably inserted. Thus, the communication hole 239 is sealed by the atmospheric valve 254 when the ink cartridge 100 is not attached to the holder of the ink jet recording apparatus.

FIG. 8 is a rear view showing a state before the film 110 is attached to the ink cartridge 100 of FIG. The atmosphere side passage, which is the side communicating with the atmosphere with the communication hole 239 as a boundary, is formed on the bottom surface of the opening 212, the meandering passage 214, the filter housing portion 216, the communication hole 218, the communication portion 222, and the communication portion 222. A communication hole 253 and a communication part 224 are included.
Specifically, as shown in FIG. 8, one end of one path 214 meandering in a maze formed on the front side of the cartridge body 120 is opened to the atmosphere as an opening 212, and the other end is ink-repellent and breathable. The filter 215 (FIGS. 4 and 5) having the above function is connected to the filter housing portion 216 in which the filter 215 is housed. The filter housing portion 216 communicates with a communication hole 218 that penetrates from the front side to the back side of the cartridge main body 120. The communication hole 218 is connected to the communication part 224 via a communication part 222 on the back side of the cartridge main body 120 and a communication hole 253 formed in the bottom of the room that defines the communication part 222. In the middle of the passage 214, a chamber 930 made of a recess is provided.

  As shown in FIG. 2, the communication portion 224 is formed as a recess 257 on the bottom surface of the cartridge main body 120, exposes the shaft portion 264 that is an operating rod of the atmospheric valve 254, and the hollow portion 232 that houses the atmospheric valve 254. A communication hole 239 capable of communication and a communication hole 253 communicating with the communication portion 222 are formed in the concave portion 257, and the outer surface of the concave portion 257 is sealed with the first ink injection port 161 and the second ink injection port 162. It is formed by sealing with a film 132. The film 132 is selected so that it can be elastically deformed by the pressing force of the protrusion protruding from the holder.

On the other hand, as shown in FIG. 6, the ink-side passage communicating with the atmosphere-side accommodation portion 270 with the communication hole 239 described above as a boundary includes a hollow portion 232, a communication hole 234 a, a communication chamber 234 b, a communication portion 234 c, a communication chamber 234 d, a communication A portion 236, a communication chamber 237, a communication hole 238, a communication groove 240, and a communication hole 242 are formed. Specifically, a through hole 234a is formed in the upper wall of the hollow portion 232, and the communication chamber 234b and a communication portion 234c formed by a notch in the upper wall of the communication chamber 234b through the through hole 234a. An air passage communicating with a communication chamber 234d provided at the upper part of the communication part 234c, a communication part 236 formed by a notch in the upper wall of the communication chamber 234d, and a communication chamber 237 with a communication hole 238 formed below. Is formed.
The communication hole 238 penetrating from the back side to the front side of the cartridge main body 120 is connected to the communication groove 240 communicating with the communication hole 238, and communicates with the communication groove 240 and through the communication hole 242 penetrating from the front side to the back side of the cartridge main body 120. It communicates with the housing part 270.
The atmosphere side accommodating portion 270, the supply side accommodating portion 290, the atmosphere valve portion 250, the atmosphere side passage, and the ink side passage are adhered to the walls partitioning the films 130 and 110 by a method such as heat welding. By this, it becomes a region isolated from the atmosphere.

The ink supply unit 160 includes a seal member 12 formed of an elastomer or the like having an insertion port 26 into which an ink supply needle provided in the holder is inserted, a supply valve 13 that closes the insertion port 26 of the seal member 12, and a supply valve And an urging member 14 made of a coil spring or the like for urging 13 toward the seal member 12. A film 604 is attached to the insertion port 26 of the seal member 12 at the time of factory shipment.
When the ink cartridge 100 is attached to the holder of the ink jet recording apparatus, the convex portion provided on the holder pushes up the shaft portion 264 of the atmospheric valve 254 through the film 132 and the ink supply needle of the holder supplies ink. The supply valve 13 of the part 160 is pushed up. As a result, the communication hole 239 communicates the atmosphere channel from the hollow portion 232 to the communication hole 242 with the atmosphere. Further, upstream of the supply valve 13 in the ink supply unit 160 communicates with the ink supply needle. When the ink cartridge 100 is loaded into the holder for the first time after shipment from the factory, the ink supply needle of the holder breaks the film 604 attached to the insertion port 26 of the ink cartridge 100 and enters the insertion port 26.

  When the ink jet recording apparatus starts recording in a state where the communication hole 242 communicates with the atmosphere, ink is supplied from the ink supply unit 160 to the recording head through the ink supply needle. When ink is supplied from the ink supply unit 160, the ink that has flowed from the ink storage unit 111 to the ink supply unit 160 in the order of the arrow a and the through hole 918 shown in FIG. 8 flows in the order of the arrow b shown in FIG. 8 and the arrows c, d shown in FIG. 6, flows into the ink supply unit 160, and is supplied to the ink supply needle inserted into the ink supply unit 160.

  In the ink storage unit 111, the ink in the atmosphere-side storage unit 270 is supplied to the supply-side storage unit 290 in accordance with the ink flow. As the ink in the atmosphere-side accommodation unit 270 is consumed, air flows from the communication hole 242 to the atmosphere-side accommodation unit 270 through the arrow f, the bottom-side communication unit 224, and the path indicated by the arrow g in FIG. . Ink is supplied from the ink supply unit 160 to the recording head to lower the liquid level of the atmosphere-side accommodation unit 270, but the flow path connecting the atmosphere-side accommodation unit 270 and the supply-side accommodation unit 290 is provided in the atmosphere-side accommodation unit 270. Since there is a communication port at the lowermost part, air does not flow into the supply-side storage unit 290 until all the ink in the atmosphere-side storage unit 270 moves to the supply-side storage unit 290.

  After all the ink in the atmosphere-side container 270 is consumed, the ink in the first ink container 292 and the second ink container 294 in the supply-side container 290 is consumed in this order. During this time, the ink in the supply side container 290 is transferred to the atmosphere side container 270 due to the surface tension of the ink meniscus formed in the second ink inlet 162 that communicates the supply side container 290 and the atmosphere side container 270. Backflow is prevented.

  When the ink in the first ink storage unit 292 starts to be consumed, air flows into the first ink storage unit 292. As a result, the liquid level of the first ink storage portion 292 is lowered. However, since only the lower portion of the first ink storage portion 292 and the second ink storage portion 294 are connected by the communication portion 276, first, the first ink storage portion 292 and the second ink storage portion 294 are connected. The ink in the container 292 is consumed. When the ink in the first ink storage portion 292 is consumed and the liquid level reaches the communication portion 276, the air also enters the second ink storage portion 294 as the ink in the second ink storage portion 294 is consumed. Inflow. While the ink in the second ink storage portion 294 is consumed, surface tension is generated in the communication portion 276 due to the ink meniscus, so that the ink in the second ink storage portion 294 is prevented from flowing back to the first ink storage portion 292. The

  As described above, the ink in the atmosphere-side storage unit 270, the first ink storage unit 292, and the second ink storage unit 294 is consumed in this order. The ink storage unit 111 is supplied to the ink supply unit 160 through the passage 918 from the communication unit 278 disposed in the vicinity of the wall 272 that substantially bisects the ink storage unit 111.

  FIG. 9 is an enlarged view of a part of the second ink storage portion 294 shown in FIG. 6, and FIG. 10 is a cross-sectional view of the second ink storage portion 294 shown in FIG. FIG. 11 is an enlarged view of the liquid level sensor 700 shown in FIG. As shown in FIG. 9, a slant wall 273 and a vertical wall 275 are formed in the second ink storage portion 294.

The oblique wall 273 extends obliquely up and down. The inclined wall 273 has an end on the communication portion 276 side facing down, and divides the inside of the second ink storage portion 294 into a second ink storage portion main body 294a and a sensor placement portion 294b. Further, the upper and lower ends of the inclined wall 273 are separated from the cartridge main body 120 and the wall 271, respectively, and form an upper gap portion 602 and a lower gap portion 603, respectively. The upper gap portion 602 allows air to flow from the second ink containing portion main body 294a into the sensor placement portion 294b when the liquid level drops. The lower gap portion 603 supplies ink from the sensor placement portion 294b to the second ink storage portion main body 294a. Here, since the lower gap portion 603 is closer to the first ink storage portion 292 than the communication portion 276, bubbles generated in the communication portion 276 do not flow into the sensor placement portion 294b. The lower clearance 603 is an example of an air inlet.
The vertical wall 275 extends vertically in the vicinity of the lower portion of the inclined wall 273 on the second ink storage unit main body 294a side.

As shown in FIG. 9, the sensor placement unit 294 b is provided with a liquid level sensor 700 that detects the liquid level of ink, and a sensor peripheral wall 500 that surrounds the periphery 530 of the liquid level sensor 700. The liquid level sensor 700 is disposed on the first ink containing portion 292 side from the lower gap portion 603 in the horizontal direction, and has a structure shown in FIG. That is, a through hole 702a is formed at the center of the plate material 702, and the sensor chip 701 is welded to the plate material 702 so as to close the through hole 702a from the outside. The sensor chip 701 has a structure shown in FIG. That is, a through hole 710a is formed at the center of the chip base 710, and the diaphragm 703 is laminated so as to close the through hole 710a from the outside. Further, on the outside of the vibration plate 703, a lower electrode 705, a piezoelectric vibrating body 704, and an upper electrode 706 are laminated in this order. The lower electrode 705 and the upper electrode 706 are connected to a connection terminal 709 and a connection terminal 708, respectively. Note that the upper electrode 706 is electrically connected to the connection terminal 708 through the conductive plate 707. The connection terminal 708 and the connection terminal 709 are formed so as to protrude slightly outward from the others. The sensor chip 701 is disposed so that the through hole 710 a of the chip base 710 is concentric with the through hole 702 a of the plate material 702.
When the liquid level sensor 700 detects the liquid level, the piezoelectric vibrating body 704 receives a signal and generates vibration. After the signal input is finished, vibration remains in the piezoelectric vibrating body 704. The characteristics of this residual vibration are different when the diaphragm 703 is in contact with the liquid surface and when it is in contact with air. For this reason, the liquid level sensor 700 can detect that the liquid level has fallen below the liquid level sensor 700.

As shown in FIG. 9, the liquid level sensor 700 is surrounded by the sensor peripheral wall 500 on the upper side and both sides, and the lower side is open. Specifically, the sensor peripheral wall 500 is formed in an inverted U shape, and has a substantially semicircular upper portion 510 that is convex upward, and legs that extend downward from both lower ends of the upper portion 510. Part 520. The length of the foot 520 is approximately half the inner diameter of the upper portion 510. The sensor peripheral wall 500 is disposed so that the liquid level sensor 700 is positioned at the center of a semicircle forming the upper portion 510. The sensor peripheral wall 500 is located on the first ink containing portion 292 side (right side in FIG. 9) from the lower gap portion 603 in the horizontal direction.
For example, the inner diameter of the upper portion 510 is substantially equal to the average value of the outer diameters of the bubbles formed when air flows into the sensor placement portion 294b. The inner diameter is smaller than the inner diameter of the circular opening 121 of the cartridge body 120. For example, the inner diameter of the circular opening 121 is 6 mm or more, and the inner diameter of the upper portion 510 is less than this. When the ink is pigment ink, the inner diameter of the upper portion 510 is, for example, 3 mm.

  As shown in FIG. 10, the sensor peripheral wall 500 rises from the surface on which the liquid level sensor 700 is fixed toward the film 130 that forms a surface opposite to the surface. The height of the sensor peripheral wall 500 is approximately half of the distance from the surface on the side where the liquid level sensor 700 is fixed to the film 130. Thus, the sensor peripheral wall 500 has a gap between the film 130.

In such a configuration, a change in the liquid level when ink is supplied from the second ink storage unit 294 will be described with reference to FIGS. 12 is a cross-sectional view taken along the line AA of the second ink containing portion 294 shown in FIG. 9 when the ink level is lower than the upper end of the sensor peripheral wall 500 and higher than the level sensor 700. FIG. FIG. 10 is a cross-sectional view taken along the line AA of the second ink storage portion 294 shown in FIG. FIG. 14 is a cross-sectional view taken along the line AA of the second ink containing portion 294 in a state where the ink is lower than the lower end of the sensor peripheral wall 500.
When ink is supplied from the second ink storage unit 294, air flows from the communication unit 276. The inflowing air becomes bubbles and rises in the ink along the inclined wall 273, and bubbles are formed on the liquid surface of the ink in the second ink containing portion main body 294a. Since the sensor peripheral wall 500 and the liquid level sensor 700 are located on the first ink storage portion 292 side (right side in FIG. 9) from the lower gap portion 603, bubbles do not enter the sensor peripheral wall 500.

  As ink is further supplied, the liquid levels of the second ink storage unit main body 294a and the sensor arrangement unit 294b are lowered as shown in FIG. At this time, air flows from the second ink containing portion main body 294a into the sensor placement portion 294b, and bubbles are newly formed. In addition, a part of the bubbles formed in the second ink storage unit main body 294a enters the sensor placement unit 294b through the upper gap 602.

  The liquid level is lower than the upper end of the sensor peripheral wall 500 and is substantially equal to the liquid level sensor 700. At this time, as shown in FIG. 13, the bubbles enter the sensor peripheral wall 500 and adhere to the liquid level sensor 700. Bubbles adhering to the liquid level sensor 700 are held by the sensor peripheral wall 500 and do not move. Therefore, after bubbles are attached, the output of the liquid level sensor 700 is stabilized. Further, since the inner diameter of the upper portion 510 is substantially equal to the average value of the outer diameters of the bubbles formed when air flows into the sensor arrangement portion 294b, for example, the bubbles are stabilized inside the sensor peripheral wall 500. In addition, when one bubble adheres to the liquid level sensor 700, the output of the liquid level sensor 700 is stabilized with the same characteristics as those in contact with air. Further, when a plurality of bubbles enter the inside of the sensor peripheral wall 500 and the wall portion at the boundary between the bubbles and the bubbles is attached to the liquid level sensor 700, the output of the liquid level sensor 700 is the same as that in contact with the ink. Stable with characteristics. In the former case, the liquid level sensor 700 detects that the liquid level has fallen below the liquid level sensor 700 at this stage.

  Then, as shown in FIG. 14, when the liquid level further decreases, the lower part of the sensor peripheral wall 500 is opened, so that the bubbles held inside the sensor peripheral wall 500 are broken, and the liquid level sensor 700 Touch. When the wall portion at the boundary between the bubbles is attached, the liquid level sensor 700 detects that the liquid level has dropped below the liquid level sensor 700 at this stage.

  As described above, according to the present embodiment, since the sensor peripheral wall 500 surrounds the upper part and both sides of the liquid level sensor 700, bubbles attached to the liquid level sensor 700 are held by the sensor peripheral wall 500, Stabilize. For this reason, the output of the liquid level sensor 700 is stabilized. Therefore, the liquid level sensor can reliably detect that the liquid level has fallen below the liquid level sensor 700.

  The sensor peripheral wall 500 is not limited to the shape and size described above. The sensor peripheral wall 500 may be formed integrally with the cartridge main body 120, or may be formed separately from the cartridge main body 120 and then joined to the cartridge main body 120 by vibration welding, ultrasonic welding, or the like. Good. In the latter case, the cartridge main body 120 can be shared by joining the sensor peripheral walls 500 formed in different shapes according to the physical properties and characteristics of the ink, the structure of the cartridge main body 120, and the like.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

2 is a front perspective view of the ink cartridge 100. FIG. FIG. 3 is a rear perspective view of the ink cartridge 100 before a film 110 is attached. FIG. 3 is a rear perspective view of the ink cartridge 100 after a film 110 is attached. 2 is an exploded perspective view of the ink cartridge 100. FIG. 2 is an exploded perspective view of the ink cartridge 100. FIG. FIG. 3 is a front view of the ink cartridge 100 before a film 130 is attached. FIG. 3 is a front view of the ink cartridge 100 after a film 130 is attached. FIG. 3 is a rear view of the ink cartridge 100 before a film 110 is attached. FIG. 6 is an enlarged view of a part of a second ink storage unit 294. FIG. 10 is a cross-sectional view of the second ink storage portion 294 in the AA cross section of FIG. 9. 4 is an enlarged cross-sectional view showing a structure of a sensor chip 701. FIG. It is a figure which shows the cross section of the 2nd ink accommodating part 294 with a liquid level. It is a figure which shows the cross section of the 2nd ink accommodating part 294 with a liquid level. It is a figure which shows the cross section of the 2nd ink accommodating part 294 with a liquid level.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Ink cartridge, 120 ... Cartridge main body, 130 ... Film, 121 ... Circular opening part, 271 ... Wall, 273 ... Oblique wall, 275 ... Vertical wall, 276 ... Communication part, 292 ... 1st ink accommodating part, 294 ... Second ink container, 294a ... second ink container body, 294b ... sensor placement part, 296 ... channel part, 500 ... sensor peripheral wall, 510 ... upper part, 520 ... foot part, 530 ... periphery, 602 ... upper gap 603 ... Lower gap part, 700 ... Liquid level sensor, 702 ... Plate material, 702a ... Through hole, 703 ... Vibration plate, 704 ... Piezoelectric vibrator, 705 ... Lower electrode, 706 ... Upper electrode, 707 ... Conductive plate, 708 ... Connection terminal, 709 ... Connection terminal

Claims (3)

A liquid cartridge that is mounted on a liquid ejecting apparatus and supplies liquid to the liquid ejecting apparatus,
A cartridge body having a bottomed housing shape having an opening on a side surface and having a liquid storage portion for storing a liquid;
A liquid level sensor for detecting the liquid level of the liquid container;
A sensor peripheral wall provided to stably hold bubbles adhering to the liquid level sensor, surrounding the liquid level sensor from above and from both sides, and opening the lower side of the liquid level sensor;
A film for sealing the opening of the cartridge body;
A circular opening provided at a position where the liquid level sensor of the cartridge body is disposed;
With
The liquid level sensor has a piezoelectric vibrating body, detects a liquid level based on residual vibration in the piezoelectric vibrating body,
The liquid level sensor and the sensor peripheral wall are arranged on a side surface facing the film,
The sensor peripheral wall is arranged to rise from the side surface having the liquid level sensor toward the film, and has a gap between the film and the film.
The sensor peripheral wall has a substantially inverted U-shape, a substantially semicircular upper part, and a foot part extending downward from each of the two lower ends of the upper part by approximately the same length as the half of the inner diameter of the upper part. Have
The inner diameter of the upper part of the sensor peripheral wall is smaller than the inner diameter of the circular opening, and is substantially equal to the average value of the outer diameters of the bubbles,
The liquid level sensor is a liquid cartridge arranged at the center of a semicircle forming the upper part. The liquid storage unit further includes an air inflow port disposed below the sensor peripheral wall,
The liquid cartridge according to claim 1, wherein the sensor peripheral wall is disposed at a position different from the air inlet in the horizontal direction.   The liquid cartridge according to claim 1, wherein the sensor peripheral wall is formed separately from the main body of the liquid cartridge and then joined to the main body.

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