LIQUID CARTRIDGE AND METHOD FOR MANUFACTURING THE SAME

A liquid cartridge includes a liquid container configured to store a liquid, a lid part configured to cover the liquid container, a liquid holding member stored in the liquid container and configured to hold the liquid, and a projection member connected to the liquid holding member, wherein the liquid holding member has a first surface facing the lid part, wherein the lid part includes an atmosphere communication path that communicates inside and outside of the liquid container, wherein the atmosphere communication path includes an opening that is open to the inside of the liquid container, and wherein the projection member projects from the first surface toward the lid part, and surrounds at least a portion of the opening as viewed from a vertical direction orthogonal to the first surface in which the lid part covers the liquid container.

BACKGROUND

Field of the Disclosure

The present disclosure relates to a liquid cartridge and a manufacturing method of the same.

Description of the Related Art

As a liquid cartridge that stores ink and is attached to an inkjet recording apparatus, there is known a liquid cartridge that includes a negative pressure generation unit that generates a negative pressure inside the liquid cartridge. Japanese Patent Application Laid-Open No. 6-191046 discusses a liquid cartridge that includes a liquid holding member that is made of a porous body as a negative pressure generation unit. The liquid cartridge discussed in Japanese Patent Application Laid-Open No. 6-191046 includes an atmosphere communication path that communicates the inside and the outside of the liquid cartridge to prevent an excessive rise in the negative pressure inside the liquid cartridge. There is provided a space portion between the liquid holding member and the upper lid of the liquid cartridge.

Under a reduced pressure or at a high temperature outside the liquid cartridge, a portion of ink may leak out from the liquid holding member and there may be little ink contained in the liquid holding member (hereinafter, such a liquid will be called free liquid). Most of the free liquid remains in the space portion, but a portion of the free liquid may intrude into the atmosphere communication path, thereby blocking the atmosphere communication path. Accordingly, the liquid cartridge may become hermetically sealed so that the liquid is no longer stably supplied to a liquid discharge apparatus, which results in the deterioration of the recording quality of the liquid discharge apparatus. This issue also applies to liquid cartridges storing a liquid other than ink.

SUMMARY

Aspects of the present disclosure provide a liquid cartridge that is unlikely to cause a blockage in an atmosphere communication path.

According to an aspect of the present disclosure, a liquid cartridge includes a liquid container configured to store a liquid, a lid part configured to cover the liquid container, a liquid holding member stored in the liquid container and configured to hold the liquid, and a projection member connected to the liquid holding member, wherein the liquid holding member has a first surface facing the lid part, wherein the lid part includes an atmosphere communication path that communicates inside and outside of the liquid container, wherein the atmosphere communication path includes an opening that is open to the inside of the liquid container, and wherein the projection member projects from the first surface toward the lid part, and surrounds at least a portion of the opening as viewed from a vertical direction orthogonal to the first surface in which the lid part covers the liquid container.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, some embodiments of the present disclosure will be described.FIG.1Ais a perspective view of a liquid cartridge1according to a first embodiment when seen from the side of a liquid discharge unit4andFIG.1Bis a perspective view of the liquid cartridge1when seen from the side of a lid part3.FIG.1Cis an exploded perspective view illustrating a liquid container2, a recording element substrate5, and an electrical wiring member6, andFIG.1Dis an exploded perspective view illustrating the liquid container2, a liquid holding member7, and the lid part3.FIG.2is a lateral cross-sectional view of the liquid cartridge1taken along line A-A illustrated inFIG.1B.FIG.3Ais an enlarged view of a part A inFIG.2(cross-sectional view taken along line B-B inFIG.3B), andFIG.3Bis a plan view of a projection member11and its vicinity. The following description is provided with reference toFIGS.1A to3Bas appropriate. The direction in which the lid part3covers the liquid container2will be referred to as Z direction. The Z direction substantially coincides with the vertical direction. The Z direction coincides with a direction orthogonal to a first surface S1of the liquid holding member7when the liquid cartridge1is attached to the main body of a liquid discharge apparatus. The long-side direction of the liquid holding member7will be referred to as X direction, and the short-side direction of the liquid holding member7will be referred to as Y direction. The X direction coincides with the direction of vibration generated at the time of vibration-welding of the lid part3to the liquid holding member7. The X direction, the Y direction, and the Z direction are orthogonal to one another. In the following description, the terms “upper side” and “lower side” are defined in a state in which the liquid cartridge1is attached to the main body of the liquid discharge apparatus. The liquid cartridge1in which the liquid has run out is replaced with a new liquid cartridge1. The liquid cartridge1is integrated with the recording element substrate5but may be separated from the recording element substrate5. The liquid cartridge1may be a filling type liquid cartridge. In the following embodiments, the liquid refers to ink. However, the liquid is not limited to ink but may be any liquid that is dischargeable from the liquid discharge apparatus.

Overall Configuration

The liquid cartridge1includes the liquid container2that contains a liquid, the lid part3that is provided on the liquid container2to cover the liquid container2, and the liquid discharge unit4that is provided under the liquid container2on the side opposite to the lid part3. As viewed from the Z direction, the liquid discharge unit4is provided at a position eccentric to the center of the liquid container2. The liquid cartridge1is mounted on a movable carriage (not illustrated) and performs a recording operation while moving. The liquid container2and the lid part3are manufactured by injection-molding using a resin. The internal space of the liquid container2is substantially in the shape of a rectangular parallelepiped, and has an opening that faces the lid part3. The liquid container2stores a liquid holding member7holding a liquid.

The liquid discharge unit4includes a recording element substrate5. The recording element substrate5includes an energy generation element (not illustrated) that applies discharging energy to the liquid. The energy generation element includes an electro-thermal converter (heater). However, the energy generation element may be any kind of element such as a piezoelectric element as long as the energy generation element can apply discharging energy to the liquid.

The liquid stored in the liquid container2is supplied to the liquid discharge unit4through a liquid supply port10at the lower part of the liquid container2, and is discharged from the energy generation element of the recording element substrate5onto a recording medium. An electrical wiring member6is bonded to the liquid container2. The electrical wiring member6includes a conductor (not illustrated) for sending electric power or control signals to the recording element substrate5and is electrically connected to the recording element substrate5.

Liquid Holding Member7

The liquid holding member7is arranged in the internal space of the liquid container2to absorb and hold a liquid L1under a negative pressure. The liquid holding member7is made of a porous body. The liquid holding member7is substantially in the shape of a rectangular parallelepiped, and occupies most of the internal space of the liquid container2. The liquid holding member7has a first surface S1that faces the lid part3and is almost planar.

The lid part3is substantially in the shape of a flat plate. The lid part3has a second surface S2that faces the liquid holding member7and is almost planar. The lid part3has a protrusion part12that protrudes from the second surface S2toward the liquid holding member7. The protrusion part12has the shape of a truncated cone that is decreased in cross-section area toward a leading end portion12A. The protrusion part12is provided with an atmosphere communication path13that is concentric with the protrusion part12and communicates the inside and the outside of the liquid container2. The atmosphere communication path13has a first opening13A that is open to the inside of the liquid container2and a second opening13B that is open to the atmosphere. The first opening13A of the atmosphere communication path13is separated from the first surface S1of the liquid holding member7. A space portion15filled with air is formed between the first surface S1of the liquid holding member7and the second surface S2of the lid part3. The lid part3has a plurality of ribs9that protrudes from the second surface S2to abut or press the liquid holding member7. Accordingly, the liquid holding member7is stably held inside the liquid container2. The ribs9each have a shape combined by lines extending in at least two directions, such as T shape, V shape, or L shape, as viewed from the Z direction.

The liquid cartridge1includes the projection member11that is connected to the liquid holding member7. As viewed from the Z direction, the projection member11is located in almost the center of the liquid holding member7, and is at a position different from the liquid supply port10. The projection member11is fixed to the liquid holding member7and protrudes upward in the Z direction from the first surface S1toward the lid part3. The projection member11is made of a porous body, as with the liquid holding member7.

It is desirable that the liquid holding member7has a melting point similar to the melting point of the projection member11(a melting point within a predetermined range). More desirably, the projection member11is made of the same material as the liquid holding member7. A ring-shaped welding part14is provided on the outer peripheral portion of projection member11, and the ring-shaped welding part14is in contact with the liquid holding member7to weld the projection member11to the liquid holding member7. The projection member11may be molded integrally with the liquid holding member7. However, in terms of costs including manufacturing and logistic costs, the projection member11is desirably a member separate from the liquid holding member7. The projection member11is a circular tube that is concentric to the first opening13A and the atmosphere communication path13. That is, as viewed from the Z direction, the projection member11is in the shape of a circular ring that surrounds the entire periphery of the first opening13A of the atmosphere communication path13. Alternatively, the projection member11may have a polygonal shape as viewed from the Z direction. As viewed from the Z direction, the distance between the projection member11and the first opening13A of the atmosphere communication path13is shorter than the distance between each of the plurality of ribs9and the center of the first opening13A. That is, as viewed from the Z direction, the distance between any position in the projection member11and the center of the first opening13A is shorter than the distance between a position of any rib9and the center of the first opening13A. In the Z direction, a leading end portion11A of the projection member11is located between the first surface S1and the second surface S2and is located between the second surface S2and the leading end portion12A of the protrusion part12.

FIG.4A to4Care diagrams illustrating a problem with a liquid cartridge101according to a comparative example. The liquid cartridge101according to the comparative example has a configuration similar to that of the liquid cartridge1in the first embodiment except for absence of the projection member11. When the lid part3is vibration-welded to the liquid container2as described below, the ribs9of the lid part3press the liquid holding member7so that the liquid holding member7may become deformed to generate a free liquid L2as illustrated inFIG.4A. If the internal pressure of the liquid container2fluctuates in this state due to a change in the external pressure, an air flow is generated toward the first opening13A of the atmosphere communication path13as illustrated inFIG.4Bso that a portion of the free liquid L2may intrude into the atmosphere communication path13. There is also a possibility that the free liquid L2may flow to a position immediately below the first opening13A and may scatter due to vibration generated in the liquid cartridge101when the carriage moves. Then, the scattered free liquid L2may intrude into the atmosphere communication path13. As illustrated inFIG.4C, the free liquid L2having intruded into the atmosphere communication path13may block the atmosphere communication path13so that the internal space of the liquid container2is hermetically sealed. Accordingly, the liquid may not be stably supplied to the liquid discharge unit4.

FIGS.3A and3Billustrate a state in which the projection member11captures the flowing free liquid L2. The projection member11prevents the free liquid L2from intruding into the atmosphere communication path13so that communication through the atmosphere communication path13is likely to be secured. Accordingly, the liquid is stably supplied to the liquid discharge unit4, and the high-quality recording is maintained. In particular, the leading end portion11A of the projection member11is located between the second surface S2and the leading end portion12A of the protrusion part12, which decreases the amount of the free liquid L2that flows from the outside of the projection member11over the leading end portion11A of the projection member11, and intrudes inside the projection member11. Therefore, it is possible to effectively prevent intrusion of the free liquid L2into the atmosphere communication path13. Since the liquid is unlikely to leak from the second opening13B of the atmosphere communication path13, the yield rate of liquid cartridges1can be improved in the manufacturing process, thereby achieving reduction in the cost of the liquid cartridge1. In the present disclosure, the leading end portion11A of the projection member11needs not necessarily be located between the second surface S2and the leading end portion12A of the protrusion part12. In an extreme example, the protrusion part12may not be provided.

A distance h2in the Z direction between the leading end portion11A of the projection member11and the leading end portion12A of the protrusion part12is desirably ⅖ or more and ⅘ or less of an entire length h1of the protrusion part12. For example, if the entire length h1of the protrusion part12is 1.5 mm, the distance h2is desirably 0.6 mm or more and 1.2 mm or less. Since h2≤(⅘)×h1, a gap G is secured between the leading end portion11A of the projection member11and the second surface S2, so that when the lid part3is vibration-welded, the projection member11is unlikely to come into contact with the second surface S2of the lid part3. This decreases a possibility that the lid part3presses the projection member11into the liquid holding member7to generate the free liquid L2inside the projection member11. In addition, this also decreases a possibility that the projection member11becomes separate from the first surface S1of the liquid holding member7and is shifted in position due to the impact of vibration welding of the lid part3. Although, as described above, the leading end portion11A of the projection member11is located between the second surface S2and the leading end portion12A of the protrusion part12(h2>0), it is further desirable to satisfy h2≥(⅖)×h1. This further decreases a possibility that the dispersed free liquid L2flows over the leading end portion11A of the projection member11and intrudes into the projection member11, and thus it is possible to more effectively prevent intrusion of the free liquid L2into the atmosphere communication path13.

As viewed from the Z direction, the projection member11surrounds the entire periphery of the first opening13A. Thus, as illustrated inFIG.3B, the projection member11can capture and absorb the free liquid L2even if the free liquid L2collides with the projection member11from any direction. Since the projection member11is formed of a porous member, the projection member11efficiently absorbs and holds the dispersed free liquid L2. This further effectively prevents the free liquid L2from flowing over the projection member11and intruding into the atmosphere communication path13.

The inner periphery of the projection member11is separated by a predetermined distance w from the outer periphery of the leading end portion12A of the protrusion part12. The predetermined distance w is desirably 1.2 times or more longer than an amplitude with which the lid part3is vibration-welded to the liquid container2, and is desirably equal to or shorter than the entire length h1of the protrusion part12. If the projection member11is separated excessively far from the first opening13A, the projection member11is less likely to capture the dispersed free liquid L2. If the projection member11is too close to the first opening13A, there arises a possibility that the protrusion part12comes into contact with the projection member11at the time of vibration-welding of the lid part3, so that the projection member11is pressed into the liquid holding member7due to the impact of the contact and the free liquid L2is generated inside the projection member11. For example, if the X-direction amplitude at the time of vibration-welding is 0.8 mm and the entire length h1of the protrusion part12is 1.5 mm, the distance w is desirably about 1.0 mm or more and 1.5 mm or less.

Manufacturing Method of Liquid Cartridge1

FIGS.5A to5Care schematic diagrams illustrating the process of welding the lid part3to the liquid container2. The recording element substrate5and the electrical wiring member6illustrated inFIG.1Care attached to the liquid container2, and then the liquid holding member7is stored in the liquid container2. Next, the projection member11is attached to the liquid holding member7, the liquid container2is filled with the liquid, and the liquid holding member7is impregnated with the liquid to hold the liquid therein. After that, the lid part3is welded to the liquid container2filled with the liquid. Specifically, as illustrated inFIG.5A, the lid part3held by a jig22is aligned with the liquid container2held by a jig21, and the lid part3is lowered and pressed against the liquid container2as illustrated inFIG.5B. In this state, the lid part3is vibrated in the X direction, and the lid part3and the liquid container2are welded together by their respective contact surfaces. After that, the lid part3is released from the jig22and the jig22is raised as illustrated inFIG.5C.

FIGS.6A and6Bare schematic diagrams illustrating the process of welding the projection member11to the liquid holding member7.FIG.6Ais a plan view of the liquid holding member7on which the projection member11is arranged, andFIG.6Bis a cross-sectional view taken along line C-C illustrated inFIG.6A. The projection member11is accurately arranged on the first surface S1of the liquid holding member7with respect to a predetermined reference position23in the liquid container2. The projection member11is attached to the first surface S1of the liquid holding member7so as to protrude upward (toward the lid part3). Next, the welding part14of the projection member11is pressed and heated using a thermal welding horn24while the projection member11is held on the first surface S1. When the welding part14is heated by the thermal welding horn24, the welding part14becomes melted. Accordingly, the first surface S1of the liquid holding member7becomes melted, and then the projection member11is bonded to the liquid holding member7. In particular, if the melting point of the projection member11is set to a melting point similar to that of the liquid holding member7, the two members become melted at the same time, thereby enhancing the reliability of welding.

FIG.7Ais a partial enlarged view of a liquid cartridge1according to a secondary embodiment andFIG.7Bis a plan view of a projection member11and its vicinity, which correspond toFIGS.3A and3B, respectively. As viewed from the Z direction, the projection member11has an open shape with two end portions16A and16B and surrounds only a portion of a first opening13A. The projection member11is a portion of a circular tube concentric to the first opening13A, and the inner periphery of the projection member11is separated by a predetermined distance w from the outer periphery of a leading end portion12A of a protrusion part12as in the first embodiment (seeFIG.3). The predetermined distance w is desirably 1.2 times longer than an amplitude at the time of vibration-welding of a lid part3to a liquid container2and is desirably equal to or shorter than the entire length of the protrusion part12. As viewed from the Z direction, the projection member11is substantially in the shape of a semi-circle. Alternatively, the projection member11may be in the shape of a polygon. As in the first embodiment, as viewed from the Z direction, a liquid supply port10is eccentric to the center of the liquid container2and the first opening13A of the atmosphere communication path13is located at a position different from the liquid supply port10(seeFIG.2). In order to stably supply the liquid from the liquid supply port10to a liquid discharge unit4, a large amount of the liquid may be injected to the upper part of the liquid discharge unit4(the liquid supply port10). In this case, the free liquid L2is likely to occur on the side provided with the liquid discharge unit4. In the present embodiment, if a part where the free liquid L2is likely to occur can be predicted in advance, the projection member11is provided only between that part and the first opening13A of the atmosphere communication path13. The projection member11is desirably provided at least between the first opening13A and the liquid discharge unit4. According to the second embodiment, the use amount of material for the projection member11can be suppressed, thereby producing an effect of reducing cost.

FIGS.8A to8Dillustrate modification examples of the present embodiment.FIGS.8A to8Dare plan views similar toFIG.7Band do not illustrate the welding part14. As viewed from the Z direction, the projection member11may have a shape formed of three rectangular sides as illustrated inFIG.8A, or may have a V shape as illustrated inFIG.8B. That is, the projection member11may have a shape formed of a combination of a plurality of straight lines. As viewed from the Z direction, the projection member11may have a C shape (an arc shape surrounding ½ or more and ¾ or less of the entire periphery of the first opening13A of the atmosphere communication path13) as illustrated inFIG.8C. That is, the projection member11may have a shape formed of any one curved line.

Although not illustrated, the projection member11may have a shape formed of a combination of at least one curved line and at least one straight line. In these modification examples, the projection member11is provided only between the part where the free liquid L2is likely to occur and the first opening13A of the atmosphere communication path13. As illustrated inFIG.8D, the projection member11may have a shape formed of one straight line. In this case as well, the projection member11is provided only between the part where the free liquid L2is likely to occur and the first opening13A of the atmosphere communication path13, and is desirably arranged in particular in parallel to the flowing direction of the free liquid L2. According to these modification examples as well, the use amount of material for the projection member11can be suppressed, thereby producing an effect of reducing cost. As can be understood from the first and second embodiments, the projection member11surrounds at least a portion of the opening as viewed from the Z direction.

FIG.9Ais a partial enlarged view of a liquid cartridge1according to a third embodiment andFIG.9Bis a plan view of a projection member11and its vicinity, which correspond toFIGS.3A and3B, respectively. As viewed from the Z direction, a plurality of projection members11C and11B is concentrically provided around a first opening13A. According to this configuration, even if a free liquid L2flows over the outer projection member11C and intrudes to the inner side of the outer projection member11C, the inner projection member11B blocks the free liquid L2so that it is possible to further effectively prevent the free liquid L2from intruding into an atmosphere communication path13. A welding part14is located between the outer projection member11C and the inner projection member11B, and is integrated with the outer projection member11C and the inner projection member11B. Accordingly, the shapes of the projection members11C and11B can be stabilized and the projection members11C and11B can be attached to the liquid holding member7by one welding process.

According to the present disclosure, it is possible to provide a liquid cartridge that is unlikely to cause a blockage in an atmosphere communication path.

This application claims the benefit of priority from Japanese Patent Application No. 2022-067564, filed Apr. 15, 2022, which is hereby incorporated by reference herein in its entirety.