Fluid cartridge for a fluid supply system

FLUID CARTRIDGE FOR A SUPPLY SYSTEM

FLUID

BACKGROUND

The present description relates generally to fluid cartridges, and more particularly, to a fluid cartridge for a fluid delivery system.

Inkjet printers generally use replaceable fluid cartridges to deliver ink and / or other fluids to a printing device in order to form an image on the media. Some fluid cartridges include two or more internal chambers configured to contain the ink, in which the chambers are often separated by a wall that has an air / ink exchange orifice formed therein. An air / ink exchange port provides air and / or ink communication between the chambers. The ink is selectively taken from one or more of the chambers and delivered and ejected through the nozzles of a print head and then onto the print medium. However, in some cases, fluid may continue to flow through the print head, even when the print head is not driven by the printer.

To prevent the free flow of ink, when the print head is not in use, a negative or back pressure is formed inside the ink cartridge that exceeds the pressure in the print head when the print head is not in use. Thus, a vacuum is formed in the ink chamber without the cartridge that holds the ink there. Back pressure inside the ink chamber without the cartridge is generally maintained by capillary force and the flow of air and / or ink back and forth through an air / ink exchange port. Difficulties may arise, however, in maintaining counter pressure in the cartridge when additional unwanted air enters an air / ink exchange port for various leakage regions that may form during the construction of the fluid cartridge.

Other difficulties can arise from a lack of desirable back pressure. For example, if a cartridge does not provide enough pressure, the ink can drool the nozzles on the orifice plate, and then it can be pulled by the counter pressure of another color cartridge. This can result in an undesirable color mix.

EUA-6505923 describes a fluid cartridge of a printing device comprising a box, a wall separating the box in a first and a second chamber and an air / ink exchange port providing fluid communication between the two chambers.

The present invention provides a fluid cartridge according to claim 1. Preferred embodiments of the invention are defined in the dependent claims.

DESCRIPTION OF THE DRAWINGS

The characteristics and advantage (s) of the embodiment (s) of the present description will be evident by reference to the following detailed description and drawings, in which the reference numbers correspond to similar components, although not necessarily identical. Reference numerals that have a previously described function may not necessarily be described in relation to other drawings in which they appear.

FIG. 1 is a perspective view from above of an embodiment of a fluid cartridge, as disclosed herein;

FIG. 2 is an enlarged, cross-sectional, perspective view of an embodiment of a fluid cartridge showing an air / ink exchange orifice formed therein;

FIG. 3A is a cross-sectional side view of an embodiment of the fluid cartridge along the line

3-3 of FIG. 1;

FIG. 3B is a cross-sectional side view of the fluid cartridge along line 3-3 of FIG. 1, which describes an alternative embodiment of the same;

FIG. 4 is a bottom view of an embodiment of the fluid cartridge, showing a longitudinal airflow passage;

FIG. 5 is a perspective view of an embodiment of the fluid cartridge, showing the transverse air flow path (s);

FIG. 6 is an enlarged, cross-sectional view, perspective view of another embodiment of the fluid cartridge; and

FIG. 7 is a larger, cross-sectional, perspective view of the embodiment of the fluid cartridge of Fig. 6.

DETAILED DESCRIPTION

Embodiment (s) of the fluid cartridge for the fluid supply system as disclosed herein, advantageously constricting or restricting the air flow to an air / ink exchange port from various flow paths unwanted air bubbles that can form in the fluid cartridge. This airflow constriction substantially maintains the pressure level at the rear of the cartridge, thereby reducing the flow of undesirable fluid through the nozzle (s). This new airflow constriction is advantageously achieved by the arrangement of the restricted airflow elements adjacent to the air / ink exchange port. The inclusion of these elements of the cartridge construction may also desirably extend the margin of error for accurately dimensioning and eliminating ink-absorbent materials into the cartridge.

Referring now to the drawings, FIG. 1 represents a fluid cartridge 10 for an inkjet printing device (not shown). Some non-limiting examples of inkjet printing devices include thermal printers, piezoelectric inkjet printers, continuous inkjet printers, and / or combinations thereof. The fluid cartridge 10 includes a box 12 formed by a semi-finished gouge and appropriate gouge material, such as, for example, by integral molding from a polymeric material. The box 12 includes an interior space defined by a base 14 and a continuous side wall 16 which extends around the periphery of the base 14. A lid 18 (shown in Fig. 3.) including an air vent 20 is welded, glued, or otherwise connected to the side wall 16 to delimit the inner space of the box 12. The box 12 and the lid 18 can be made of similar or dissimilar polymeric materials , which can also be opaque or transparent. Non-limiting examples of suitable polymeric materials include polypropylenes, polypropylenes bonded with polyphenylene oxide, polystyrenes, polyurethanes and combinations thereof.

A wall 22 is disposed within the box 12, positioned substantially perpendicular to the base 14 and extending outwards from the base 14. The wall 22 also abuts opposite side walls 16, thereby forming first and second chambers 24, 26 in box 12. An interface or edge 28 is formed between the wall 22 and the base 14, and between the wall 22 and an adjacent opposite side wall 16.

An ink outlet or orifice 30 is formed on the base 14, located in the second chamber 26. The ink outlet 30 generally engages with a print head collector (not shown) including a plurality of ink nozzles. The ink outlet 30 also mates with the first and / or second chambers 24, 26, thus providing fluid communication between the ink outlet 30, and the chambers 24, 26.

Referring now to FIG. 2, an air / ink exchange port 32 is defined in the lower portion of the wall 22 and located adjacent to the base 14. A port 32 is essentially a space or opening formed in the wall 22 at the interface 28, thereby exposing the wall / base interface. 28. An orifice 32 is designed to facilitate the movement of air and the circulation of paint between the first and second chambers 24, 26.

Referring now to FIG. 3, the first chamber 24 is configured to maintain a free flowing liquid ink volume and will be referred to here as a free ink chamber (FIG) 24. For drop-on-demand printing_r For example, with thermal inkjet printers or piezoelectric inkjet printers, the capillary strength of the capillary media (for example, 40, 40a absorption, described below) is generally through effort to pull the ink into outside of FIG 24 through an air / ink exchange port 32, but it is in relation to the vacuum created in FIG 24. When the air bubbles in the FIC 24 through the air / ink exchange port 32, the ink is then pulled into the medium / absorber 40, 40a until the vacuum in the FIC 24 is restored. The ink of the medium / absorber 40, 40a exits the ink outlet 30 for supplying the ink to the printing device. As the volume of ink in which the ink is exhausted in the free ink chamber 24, air is drawn into the cartridge 10 through the air conduit 20 formed in the cap 18, and passes through the second chamber 26 and into an opening orifice. air / ink exchange 32. To reach the FIC 24, it is generally desirable that the air leaving the conduit 20 passes through the means / absorbers 40, 40a, 40b, and not through creases and hollow parts around the perimeter of the means / capillary absorbers 40, 40a, 40b.

In one embodiment, and as best shown in FIG. 1, a plurality of grooves 34 can be formed in a portion on the side 36 of the wall 22, facing the second chamber 26 and substantially directly above an air / ink exchange orifice 32 and is used to facilitate the movement of air from from conduit 20 to an orifice 32. The slots 34 generally extend along the wall 22, so that when the level of ink saturation in the capillary media / absorbers 40, 40a, 40b reaches the top of the slots 34, the air can start to pass to the FIC 24, thus allowing the ink to flow into the medium / absorbents 40, 40a, 40b. The air then travels into the free ink chamber 24 and through the ink in such a way that the air is above the ink in the top portion 38 of the chamber 24. Thus, the free ink chamber 24 generally has approximately the same volume of fluid (ie, ink and air) due to the volume of ink in the free ink chamber 24 is replaced with air as the ink is removed from the cartridge 10 of the printer head.

In general, when the print head is activated, the print head causes the ink to flow through the nozzles. When the print head is deactivated, the print head through the print head restricts the flow of ink. The nozzles are still open when the print head is turned off, but the pores are small enough that the capillary force on the nozzles substantially prevents the cartridge from pulling air through the nozzles. Once the nozzles are open, in some cases, they can undesirably leak ink if the cartridge 10 fails to provide the desired counter pressure.

To substantially prevent paint dripping and / or leakage through the nozzles, a counter pressure is formed on the print head when the print head is deactivated, as mentioned briefly above. As used herein, the term counter pressure refers to a partial vacuum formed within the ink in the ink cartridge 10 to resist the flow of ink through the print head. Thus, an increase in counter pressure can be referred to as an increase in partial vacuum and is measurable in terms of the height of the water column. In general, it is desirable to maintain a sufficiently strong back pressure on the print head to substantially prevent ink dripping. It should be understood, however, that the back pressure must be adequate pressure so that the printhead overcomes the back pressure and ejects the ink when activated.

In an ideal system, the counter pressure level is desirable to be continuously maintained in the ink cartridge 10 and the print head. However, changes in back pressure can often occur, for example, during changes in the surrounding environment or with the operation of the print head. As the print head ejects an ink drop, the depletion of ink from the free ink chamber 24 increases the back pressure of the chamber 24, thereby creating a greater vacuum.

In one embodiment, and with reference to Figures 1 and 3A, the second chamber 26, also referred to here as the absorption chamber 26, is filled with an absorber 40 configured to absorb the ink from the free ink chamber 24, creating thus, the counter pressure in the free ink chamber 24. The counter pressure (vacuum) in the FIC 24 is relieved by bubbling air in the FIC 24. It should be noted that the absorber 40 has been removed from Fig. 1 by reasons of clarity. The absorber 40 is a porous medium having a high capillary strength effect (e.g., high capillary media) and a layered texture, which is generally compressible at its edges, without creating wrinkles or gaps in the porous medium. In one embodiment, the absorbent 40 is selected in such a way that it has a desired capillary strength. Capillary strengths suitable for absorber 40 can vary between about 2 '' WC (water column) to about 6 '' CC and, in an alternative embodiment, a suitable capillary strength is about 4 '^!

WC. The ink pressure increases in the free ink chamber 24, the ink is transferred to the absorber 40 and maintained in the pores thereof. To balance the back pressure in the cartridge 10, the ink made in the pores can, in some cases, be transferred back to the free ink chamber 24. For example, if descending from high altitudes, or cooling from a higher temperature, the ink will flow from the absorbent 40 to the FIC 24. During events like these, the air at FIC 24 is contracting. During normal printing, the ink can be drawn into the 40 absorber, and air will be attracted to the FIC 24 by the vacuum present in the FIC 24.

In another embodiment, and with reference now to FIG. 3B, the second chamber 26 can be filled with a first absorber 40a disposed adjacent to a second absorber 40b. The first absorber 40a is configured similarly to the absorber 40, as shown in FIG. 3A. The second absorber 40b is also a porous medium, but has a lower capillary strength effect. In a non-limiting example, the ink of the first absorber 40a is disposed under the second absorber 40b and is in fluid communication with it. In one embodiment, the second absorber 40b (for example, a weak capillarity medium (LCM)) has a capillarity force of about 3 '' WC, and the first absorber 40a (for example, a high capillarity medium ( HCM)) has a capillarity strength of about 4^fl WC. The lower capillary strength of the second absorbent 40b generally ensures that substantially all of the ink is extracted from the second absorbent 40b before draining the ink from the first absorbent 40a.

Although some examples of capillary forces are provided above for the first absorber 40a and the second absorber 40b, it is to be understood that any suitable capillary medium having a suitable capillary force can be used. Generally, the second absorber 40b provides sufficient back pressure to prevent dripping from the nozzles. The first absorbent 40a must have a higher capillary force than the second absorbent 40b. Some examples of capillary forces adhered to the second absorber 40b vary between about 2 '^!WC and about 5 '^! WC, and for the first absorbent 40a between about 3^!'WC and about 6^!'WC.

Without being linked to any theory, it is believed that it is desirable that the cartridge 10 drain substantially all of the second absorbent 40b first, and then drain a small amount of the first absorber 40a, in order to open the path of bubbles into the air to reach the FIC 24, and then consistently drain substantially all of the FIC 24 before draining additional paint from the first absorbent 40a. One of the reasons why it is believed that this method may be desirable is the low ink detection system (LOID) (not shown). A sensor configured to detect when the FIC 24 empties allows the printer to know that substantially the only ink remaining in the cartridge 10 is found in the first absorber 40a. This generally allows the printer to more accurately predict when to stop printing in order to prevent drying of the nozzles and potential damage to the print head. However, if the first absorber 40a is sometimes drained half when FIC 24 empties due, for example, to a delayed opening of the air passage through the air / ink mixing orifice 32 to FIC 24; and other times the first absorber 40a and a portion of the second absorber 40b were filled with ink, when the FICs 24 tip empty, for example, due to an unintended air path to the exchange / ink / bubbler hole 32, the system LOID can become less useful.

Since the back pressure level of cartridge 10 can be influenced by changes in the environment, operation, etc., it is generally beneficial to avoid any unwanted additional fluid, in particular air, entering the air / ink exchange port 32. As shown in FIGS. 4 and 5, the potential outdoor air paths (44, 46, generally represented by arrows describing the direction of the same) generally result from the construction of the cartridge 10. These air paths 44, 46 can penetrate the air / ink exchange port 32, and disturb the counter pressure level of cartridge 10 between chambers 24, 26. The first air path 44 (shown in figure 4.) is a substantially longitudinal air path formed in the absorbent chamber 26 along the base 14, between the ink outlet 30 and the air / ink exchange port 32. The first air path 44 can be created when the absorber 40 is disposed within the housing 12, thus leaving the small gaps between the absorber 40 and the base 14.

The other potential air path (s) 46 are substantially transverse air paths formed at the interface or edge 28, and travel transversely from the interface 28, to both sides cross sections 48, 50 of the air / ink exchange port 32. The air path (s) 46 can be created when the wall 22 is arranged inside the box 12, but not completely conformed to it thus leaving the small openings in the interface 28, which may leak into an orifice 32. For example, the air path (s) 46 may be formed by a rib, opening or bevel in the absorber 40, 40a, which allows air to flow along the corner between the absorber 40, 40a and the housing 12 .

Referring again to FIG. 1, the air path 44 may be limited or otherwise restricted by the arrangement of a longitudinal air flow limiting element 52 having two opposite sides 54, 56 adjacent to the air / ink exchange port 32 in the base 14. The longitudinal airflow limiting restriction element 52 generally extends outwardly from the wall 22 and the air / paint orifice 32 at a predetermined distance to the absorption chamber 26.

In the alternative embodiment (s), the air path (s) 46 can also be limited by the arrangement of a transverse air flow limiting element 60 in contact / adjacent to one of the two opposite faces 54, 56 of the flow of the longitudinal airflow limiting element 52.

It is to be understood that the longitudinal airflow limiting element (s) 52 can be of any suitable size, shape and / or configuration, and can be formed from any suitable material, and can be arranged in any suitable location sufficiently desirable for any limiting / restricting longitudinal airflow, as described herein.

Referring further to FIG. 1, in one embodiment, the longitudinal airflow limiting element 52 is generally a limiter such as a backrest, a step, or other similar protruding feature, which is arranged within the absorber chamber 26 between the base 14 and the absorber 40 , 40a (shown in Fig. 3A and 3B) and is arranged in the air / ink exchange port 32. In one embodiment, the longitudinal airflow limiting member 52 extends through the air / ink exchange orifice 32, and ends substantially flush with the cavity 24 facing wall 22 (as best seen in FIG. 7).

It is contemplated to be within the scope of the present disclosure that the longitudinal airflow limiting element 52 will be placed in the cartridge 10 in any suitable manner, be of any suitable thickness, and be of any suitable width.

In one embodiment, the element 52 is integrally molded with the housing 12. The thickness of the element 52 can generally be less than about 2 mm, a thickness that advantageously creates local compression of the adjacent absorbent 40, 40a. The element 52 is generally as wide as the air / ink exchange port 32, however, it may, in some cases, be beneficial for the element 52 to be wider (as shown in dashed lines in Fig. 6.) than a orifice 32. In one embodiment, an element 52 is about 3 mm wider on each side than an orifice 32. It is believed that, in some implementations, such a wider threshold 52 can result in more uniform capillary means in the orifice air / ink exchange system 32.

In general, the thickness of element 52 is relatively small, but thick enough to compress the capillaries of the absorber 40, 40a, when element 52 is arranged and installed in cartridge 10. This results in reduced compression of pore sizes / locations of the capillaries of the absorber 40, 40a, located adjacent to the element 52. Without being linked to any theory, it is believed that this reduction in pore size can generate a relatively high capillary strength, for example, about 8¹'WC, thus keeping the capillary pores full of ink, and substantially preventing air from traveling between the base 14 and the absorber 40, 40a and reaching the air / ink exchange orifice 32.

As with the longitudinal airflow restriction element 52, it is to be understood that the longitudinal airflow restriction element (s) 60 (if included) can be of any suitable size, shape and / or configuration, it can be formed from any suitable material, and it can be arranged in any suitable enough location to desirably contract / restrict the transverse air flow, as described herein.

In one embodiment, a transverse airflow limiting element 60 is arranged in the absorption chamber 26 adjacent to wall 22 and to the side 54 of the longitudinal airflow limiting element 52. If desired, a second element 60 (substantially identical to the , and the mirror image of an element 60) can be arranged on the other side 56 of the longitudinal airflow limiting element 52. In one embodiment, element (s) 60 are substantially triangular-shaped inserts (e.g., reinforcements), substantially rectangular inserts, substantially wedge-shaped quarter-circle inserts, and combinations thereof. The element (s) 60 can be positioned substantially orthogonal to the side 36 of the wall 22, facing the second chamber 26 and substantially parallel to the air / ink exchange port 32, thereby restricting or otherwise the transverse airflow path (s) 46 and to an orifice 32.

Referring now to FIGS. 6 and 7, this embodiment does not include a transverse airflow limiting element 60. In this embodiment, as well as in one of the embodiments disclosed herein, the fluid cartridge 10 may further include one or a plurality of ribs 62 formed in the base 14, in the longitudinal airflow limiting component 52, or in combinations thereof. Without being linked to any theory, it is believed that the ribs 62 form capillary pathways to facilitate or further promote the flow of the ink fluid between the free ink chamber 24 and the absorption chamber 26, when air is flowing through , or remains stationary in the air / ink exchange port 32. In one embodiment (as best seen in FIG. 6), the ribs 62 are formed at the threshold 52, which extends from the face of the wall 22 to the chamber 26 As best seen in FIG. 7, in one embodiment, the ribs 62 may extend further at the threshold 52 through the air / ink exchange port 32 and partially in FIG 24.

It is convenient for the edges formed at the base of the ribs 62 to be relatively sharp, and not substantially curved, as it is believed that the bubbles have difficulty conforming to sharp corners. It is to be understood that the ribs 62 can be of any suitable size, however, in one embodiment, the ribs 62 can be from about 0.2 mm to about 0.6 mm wide, and about 0, 2 mm to about 0.6 mm in height. In one embodiment, the ribs 62 are about 0.4 mm wide and about 0.4 mm high. The space between the ribs 62 can vary from about 0.2 mm to approximately 0.6 mm. In one embodiment, the space between the ribs is about 0.4 mm.

The ribs 62 can also work to substantially prevent air traveling through the air / ink exchange port 32 from interrupting the fluid connection between the absorber 40, 40a and the free ink chamber 24. For example, when air is quickly passed to FIC 24, you can suddenly reduce the vacuum in FIC 24 and disconnect the fluid in FIC 24 from the absorber / HCM 40, 40a. When this happens, the ink on the FIC 24 is stuck because the absorber 40, 40a cannot remove it to the absorber 40, 40a. However, with the ribs 62, it is believed that the capillaries are maintained allowing the absorber 40, 40a to pull the ink coming from the FIC 24. This ink pulled from the FIC 24 gradually increases the vacuum in the FIC 24, which creates a differential pressure to extract more air into the FIC 24. As more air is drawn into the air / ink exchange port 32, the bubbles that obstruct port 32 are substantially dislodged and float to the FIC 24, thereby restoring proper function. In addition, although a single rib 62 can function properly, in some cases, it is believed that additional reinforcements 62 can advantageously reduce the possibility of all possible capillary paths along the edges between threshold 52 and ribs 62 being blocked by air bubbles.

In one embodiment, the fluid chamber can be formed by providing the housing 12, including the base 14, the free ink chamber 24, and the absorption chamber 26. The wall 22, including air / ink exchange port 32 defined in the lower portion thereof, is arranged in the box, which extends outwardly and substantially perpendicular to the base 14, thus separating the free ink chamber 24 and the absorption chamber 26. 0 longitudinal air flow limiting member 52 is disposed in the absorption chamber 26, adjacent to the air / ink exchange port 32 and extending from there to a predetermined distance. The absorber 40, 40a can then be placed inside the absorption chamber 26 and against the element 52 so that the capillary edges of the absorber 40 are compressed, thus restricting the flow of air through the same undesirable path. of the longitudinal air flow 44.

If the transverse airflow limiting element (s) 60 is used in one embodiment, they can be arranged in the absorbent chamber 26, respectively, adjacent to the sides 54, 56 of the element 52, and adjacent to the orifice. air / ink change 32. This can be accomplished by any suitable method, however, in one embodiment, the airflow restricting elements 60 are molded into the housing 12, and the insertion of the absorber 40, 40a causes the elements 60 to pierce the means capillary or porous absorber 40, 40a substantially without distorting the capillaries. The element (s) 60 are thus formed within the chamber 26, adjacent to the air / ink exchange port 32, and substantially restrict the unwanted air flow from the transverse air flow path (s) 46. If desired, the second absorber 40b (formed from, for example, a weak capillary medium) can then be brought into contact with, and in fluid communication with, the first absorber (40a formed from, for example, one quality capillary means) before the cap 18 is attached to the box 12.

The present description provides many advantages, some of which include the following. Airflow restricting elements 52, 60 can advantageously substantially constrain / restrict undesirable airflow, for example, air paths 44, 46. Without being bound by any theory, it is believed that limiting the air flow from the air passages 44, 46 by, for example, operatively placing / forming the elements 52, 60 allows the counter pressure of the cartridge 10 to be desirably regulated between the free ink chamber 24 and the absorbent chamber 26. This can substantially prevent leakage through the nozzles. Elements 52, 60 may also allow for the simpler construction of absorbents 40, 40a, 40b. For example, in order to avoid an undesirable additional air / ink exchange orifice 32 of various air passages (non-limiting examples are defined here), the absorbers 40, 40a, 40b and may require very specific sizing cut as well as the very complicated installation procedures, in order to avoid these potential airway formations. Users 52, 60 can advantageously avoid this need for precision in the manufacture and installation of 40, 40a, 40b absorbers.

Although various embodiments have been described in detail, it will be apparent to those skilled in the art that the described embodiments can be modified as long as they fall within the scope of the invention as claimed.