Cartridge lid, cartridge, inkjet print head and inkjet printer

Abstract

The present invention relates to the field of inkjet printing technology. Cartridges whose ink reservoirs communicate with the outside environment through vents are prone to ink leakage, especially when the outside pressure changes significantly with respect to the outside pressure after ink filling due to possible air bubbles trapped in the ink reservoir. The present invention provides a cartridge lid (15) having an expansion space (25) formed between an outer lid member (40) and an inner lid member (27). The expansion space (25) communicates with the outside environment through the vent (17) and has an inlet (26) through which ink can flow into the expansion space (25). The present invention also provides a cartridge, an inkjet printhead and an inkjet printer.

Description

FIELD OF THE INVENTION

[0001]

[0001] The present invention relates to the field of inkjet printing technology, and more particularly to preventing ink from leaking out of a cartridge through a vent hole due to shipping and / or use of an inkjet printhead at an altitude different from that of the factory, and more particularly to a cartridge lid, a cartridge, an inkjet printhead, and an inkjet printer.

[0002] 1a, 1b and 2, a cartridge 37 of an inkjet printhead comprises a cartridge body 4 and a cartridge lid 15 for covering an opening 38 of the cartridge body 4. An ink reservoir 10 for containing ink is formed inside the cartridge body 4. The cartridge body 4 further comprises an ink flow opening 13 that connects the ink reservoir 10 to an ejection chamber of the inkjet printhead, and the ink flow opening 13 communicates with the ink reservoir 10 via a filter 12 and a pipe 11.

[0003]

[0003] Ink flow through the ejection nozzles of the ejection chambers of an inkjet printhead must be precisely controlled because it is one of the essential prerequisites for achieving high-end quality printing with an inkjet printer. One system that assists in providing this amount of control of ink flow is a backpressure system that creates a slight negative pressure in the fluid contained within the ink reservoir of the inkjet printhead cartridge. The negative pressure in the fluid prevents unintentional leakage of ink, which could otherwise occur when the ink-using inkjet printhead is idle or when the cartridge is subjected to sudden accelerations during handling.

[0004]

[0004] As shown in Figures 1a, 1b and 2, possible back pressure systems known in the art use a porous member 14 (e.g., open cell foam), a fibrous member, or a combination of the two, inserted into the ink reservoir 10 of the cartridge 37, as described in EP 3302983, to generate a negative pressure in the liquid contained in the ink reservoir 10, created by the capillary effect between the pore network or fibers.

[0005]

[0005] When back pressure is generated by capillary force from the porous member 14 inserted into the ink reservoir 10, the ink reservoir 10 must be in communication with the external environment. In other words, the boundary liquid level within the porous member 14 must be at atmospheric pressure. If the ink reservoir 10 is not in communication with the external environment, while the ink level in the ink reservoir 10 decreases due to ink ejection during printing, the pressure of the liquid contained in the ink reservoir 10 will drop far beyond the appropriate back pressure value, preventing the inkjet printhead from further ejecting.

[0006] To ensure proper communication with the external environment, the cartridge lid 15 is generally provided with a vent hole 17 in addition to the ink fill hole 16. Specifically, as shown in FIGS. 1a, 1b, 2, and 3, the cartridge lid 15 is provided with the ink fill hole 16, through which a needle penetrates substantially the entire porous member 14 to fill the ink reservoir 10 with ink, and the vent hole 17, which connects the ink reservoir 10 to the external environment. The vent hole 17 is located at one end of a shallow, serpentine vent channel 18 molded into the outer surface of the cartridge lid 15. The ink fill hole 16 is very large and is closed after filling (with ink) with an adhesive label 19 or plug (not shown) to prevent excessive ink evaporation. The adhesive label 19 overlaps not only the ink fill hole 16 but also the vent hole 17. The adhesive label 19 closes the top of the shallow, serpentine vent channel 18 and acts as a ceiling surface. The ventilation outlet 20 at the very end of the shallow serpentine ventilation channel 18 remains uncovered, thereby allowing the ink reservoir 10 to communicate with the external environment. The small cross-section and appropriate length of the shallow serpentine ventilation channel 18 keep the evaporation rate low and, at the same time, maintain a pressure balance between the inside and outside of the ink reservoir 10 even during printing. Of course, two separate labels (not shown) can also be suitably used for the ink fill hole 16 and the vent hole 17, respectively. As shown in FIG. 4 , in addition to the ink fill hole 16 and the vent hole 17, the inner surface of the cartridge lid 15 is generally provided with a peripheral seal frame 22 suitable for ultrasonic bonding with the cartridge body 4, a plurality of ribs 23, and an additional peripheral reinforcing frame 41 designed to appropriately strengthen the cartridge lid 15 and thereby prevent deformation or breakage of the cartridge lid 15. Typically, such ribs 23 and peripheral reinforcing frame 41 are obtained at once during the molding process of the cartridge lid 15.

[0007]

[0007] The ink filled in the ink reservoir 10 immerses most of the porous member 14. Capillary forces prevent the ink from escaping from the porous member 14. Nevertheless, ink has a certain amount of internal mobility throughout the porous member 14, especially if the porous member 14 is a fibrous member that readily allows ink movement along the fiber direction. Therefore, handling an ink-filled inkjet printhead can result in some air being trapped in the porous member 14. This trapped air can even become surrounded by the ink. Even some additional air can be trapped within the pipe 11 due to possible incorrect operation or lack of a hermetic seal between the ink fill hole 16 and the needle during the ink filling phase. Simply put, in an inkjet printhead, some islands of air can remain trapped within the ink.

[0008] After filling, atmospheric pressure surrounding the inkjet printhead is present even in the portion of the ink reservoir 10 that is free of ink, but the resulting pressure on the liquid contained in the inkjet printhead is due to atmospheric pressure, increased by the hydrostatic pressure of the liquid column, and decreased by the capillary pressure of the porous member 14. The capillary force of the porous member 14 depends on the pore size, as well as the surface tension of the ink and the wettability of the porous member material, and is carefully designed so that the pressure on the liquid contained in the ink reservoir is low relative to the external environment.

[0009]

[0009] Before the inkjet printhead is prepared for shipment, the ejection nozzles are sealed with a suitable adhesive tape to prevent ink evaporation and protect the ejection nozzles from particle contamination or mechanical damage. The inkjet printhead is finally placed in a plastic cup and thermally sealed with a double-layer plastic-aluminum packing cover. As a result, the inkjet printhead is enclosed in a sealed container with an internal pressure equal to the atmospheric pressure of the factory.

[0010]

[0010] However, during transportation of the inkjet printhead or when the inkjet printhead is intended for use at high altitudes, the sealed container may be subjected to large pressure changes. For example, in air cargo, the cargo hold may be depressurized during flight. In another example, the final destination of the inkjet printhead may be at an environmental pressure that is very different from the environmental pressure of the factory due to the different altitude. When the environmental pressure of the sealed container changes, an imbalance between the internal pressure of the sealed container and the environmental pressure may occur. The imbalance internal pressure of the sealed container pulls the packing cover outward, thereby reducing the internal pressure of the sealed container relative to the initial pressure in the factory.

[0011]

[0011] Because the ink reservoir is in communication with the area outside the cartridge through a vent, if the environment is at a pressure lower than the factory pressure, the air trapped within the porous member may expand and draw out ink, causing it to leak out of the vent when the cartridge is in a sealed container or when the end user turns over the packing cover.

[0012]

[0012] Sealing the vent outlet with an additional label or removable plug can only function to prevent ink from leaking within the sealed cup, but will not work if the final target pressure is significantly lower than the factory pressure. That is, removing the additional label or plug will cause a sudden imbalance in the internal pressure, causing ink to be sprayed out of the vent outlet. Such a phenomenon can occur even if air is not trapped in the porous member. Because communication between the liquid surface in the ink reservoir and the outside is via a short distance, allowing ink to flow almost directly outward, a sudden perturbation in the internal pressure of the sealed container can easily result in ink being sprayed out of the vent in any case.

[0013] The situation in which ink is ejected from the vent hole 17 is shown diagrammatically in FIG. 2. The relative positions of the ink reservoir 10 and cartridge lid 15 are shown in an exploded view, and the sudden ink flow 21 caused by a pressure imbalance is diagrammatically represented by an arrow. The ink quickly covers a short, direct path toward the ink fill hole 16 and vent hole 17 in the cartridge lid 5. The ink fill hole 16 is sealed by an adhesive label 19 (FIG. 3b), which also overlaps the vent hole 17 and most of the shallow serpentine vent channel 18, thereby leaving the vent outlet 20 in communication with the outside. The volume of the shallow serpentine vent channel 18 below the adhesive label 19 is very small and can be quickly filled with ink, eventually causing ink to eject from the vent outlet 20 at the very end of the shallow serpentine vent channel 18. Summary of the Invention

[0014]

[0014] In order to solve the above technical problem, the solution of the present invention consists of providing a cartridge lid having an expansion space connected to an air hole to collect possible ink flow caused by an imbalance between the internal pressure of the ink reservoir and the environmental pressure outside the ink reservoir due to changes in environmental pressure and prevent ink from leaking outside the cartridge.

[0015]

[0015] In one aspect of the present invention, a cartridge lid is provided. The cartridge lid includes an outer lid member and an inner lid member. The outer lid member is provided with an ink fill hole and a vent hole. The inner lid member is attached to the outer lid member and overlaps the vent hole. An expansion space is formed between the outer lid member and the inner lid member, and the expansion space has an inlet through which ink can flow into the expansion space, and the expansion space communicates with the external environment via the vent hole.

[0016] The cartridge lid of the present invention prevents ink from reaching areas outside the cartridge in a short travel due to direct communication, but instead forces the ink to pass through a longer expansion space, thereby dampening the force of a possible jet and providing an internal expansion volume or space that can accommodate all or most of the ink displaced due to a pressure imbalance.

[0017] Preferably, the expansion space is a circuitous expansion circuit. The circuitous shape of the expansion space increases both the damping effect and the available volume required for passage. The circuitous expansion circuit causes ink entering the expansion space from the inlet to take a longer path before expelling from the vent hole.

[0018] Preferably, the expansion space contains a porous material, which can increase the damping of the ink flow momentum without impairing the fluid communication with the outside.

[0019] Preferably, the expansion space includes a plurality of expansion chambers fluidly connected via narrow communication passages, each of the expansion chambers being surrounded by a chamber wall connected to the outer and inner cover members. The abrupt changes in width along the expansion circuit due to the plurality of narrow communication passages contribute to flow attenuation.

[0020] Preferably, the chamber wall comprises two curved walls surrounding the vent hole.

[0021] Preferably, two adjacent chamber walls are spaced apart to form a narrow communicating passage.

[0022] Preferably, the narrow passage(s) are formed in the chamber wall(s).

[0023] Preferably, the inner lid member is parallel to the outer lid member.

[0024]

[0024] In a second aspect of the present invention, there is provided a cartridge. The cartridge comprises a cartridge body and the cartridge lid as described above. The cartridge body has an opening and an ink flow opening. An ink reservoir for containing ink is formed within the cartridge body. The cartridge lid covers the opening.

[0025] Preferably, the cartridge comprises a porous and / or fibrous member inserted into the ink reservoir.

[0026]

[0026] In a third aspect of the present invention, there is provided an inkjet printhead, the inkjet printhead comprising a cartridge as described above.

[0027] Preferably, the inkjet printhead is a thermal inkjet printhead comprising a microfluidic device mounted in a cartridge. The microfluidic device comprises a plurality of resistors, a plurality of ejection chambers, and a nozzle plate. The plurality of ejection chambers are disposed above the plurality of resistors and in fluid communication with the ink flow openings. The nozzle plate covers the plurality of ejection chambers and comprises a plurality of ejection nozzles for ejecting ink from the plurality of ejection chambers.

[0028]

[0028] According to a fourth aspect of the present invention, there is provided an inkjet printer comprising the above-described inkjet printhead.

[0029]

[0029] Non-limiting and non-exhaustive embodiments of the present invention will now be described by way of example with reference to the following drawings: [Brief explanation of the drawings]

[0030] [Figure 1a] 1 shows an exploded view of a known cartridge. [Figure 1b] 1 shows a cross section of an exploded view of a known cartridge. [Figure 2] 1 shows a schematic diagram of the cartridge of FIG. 1a and FIG. 1b. [Figure 3a] FIG. 1B shows a schematic view of the exterior of the cartridge lid of the cartridge of FIGS. 1a and 1b with the adhesive label removed. [Figure 3b] 1a and 1b show schematic views of the exterior of the cartridge lid of the cartridge of FIG. [Figure 4] 1 shows a bottom view of the cartridge lid of a known cartridge. [Figure 5] 1 shows a schematic perspective view of an inkjet printhead according to an embodiment of the present invention; [Figure 6a] 6 shows an exploded view of the inkjet printhead cartridge of FIG. 5. [Figure 6b] 6 shows a cross section of an exploded view of the inkjet printhead cartridge of FIG. 5. [Figure 7] 6 shows a partial cross-sectional schematic view of the inkjet printhead microfluidic device of FIG. 5. [Figure 8] 1 shows a schematic perspective view of a cartridge lid with an inner lid member removed according to an embodiment of the present invention; [Figure 9] 1 shows a bottom view of the outer lid member of the cartridge lid according to an embodiment of the present invention. [Figure 10] 1 shows a schematic perspective view of a cartridge lid according to an embodiment of the present invention; [Figure 11] FIG. 10 shows a bottom view of a cartridge lid of a cartridge according to an embodiment of the present invention. [Figure 12] 10 shows a schematic perspective view of a cartridge lid according to another embodiment of the present invention with the inner lid member removed. FIG. [Figure 13] 10 shows a bottom view of an outer lid member of a cartridge lid according to another embodiment of the present invention. FIG. [Figure 14] 10 is a schematic view of the inner surface of an outer lid member of a cartridge lid according to yet another embodiment of the present invention. [Figure 15] 10 shows a cross-sectional view of the cartridge lid corresponding to the chamber wall. Detailed Description of the Embodiments

[0031]

[0046] To make the above and other features and advantages of the present invention more apparent, the present invention will be further described in conjunction with the accompanying drawings, in which: It should be understood that the particular embodiments of the present invention are illustrative and not intended to be limiting.

[0032]

[0047] The present invention provides a cartridge lid, a cartridge, an inkjet printhead, and an inkjet printer. Figure 5 shows a schematic perspective view of an inkjet printhead 1 according to one embodiment of the present invention. In this embodiment, the inkjet printhead 1 is a thermal inkjet printhead, such as a bubble inkjet printhead. In other embodiments, the inkjet printhead 1 may be a piezoelectric inkjet printhead.

[0033]

[0048] As shown in FIGS. 5, 6a, and 6b, the inkjet printhead 1 includes one or more cartridges 37. Each cartridge 37 may contain a different color ink. The cartridge 37 includes a cartridge body 4, typically formed from a plastic material. The cartridge body 4 has an opening 38 and an ink flow opening 13. An ink reservoir 10 for containing the ink is formed inside the cartridge body 4. A filtration device 12 is provided between the ink flow opening 13 and the ink reservoir 10. In this embodiment, the filtration device 12 is a mesh filter. Optionally, the filtration device 12 communicates with the ink flow opening 13 via a pipe 11 (e.g., a standpipe), which has an upper end at the filtration device 12 at the interface with the ink reservoir 10 and another end terminating at the ink flow opening 13.

[0034]

[0049] 5, the inkjet printhead 1 further includes a microfluidic device 2 attached to a cartridge 37. For example, the microfluidic device 2 is adhered to the cartridge body 4 of the cartridge 37 via a sealing adhesive, which provides both mechanical strength and sealing to the joint between the microfluidic device 2 and the cartridge 37. The microfluidic device 2 is in fluid communication with the ink flow opening 13 of the cartridge 37 so that ink contained in the ink reservoir 10 of the cartridge 37 can flow through the ink flow opening 13 to the microfluidic device 2. The microfluidic device 2 is electrically actuated via the contact pads 3.

[0035]

[0050] As shown in FIG. 7 , the microfluidic device 2 includes multiple ejection chambers 6 and multiple resistors 5 corresponding to the multiple ejection chambers 6. The ejection chambers 6 are located above the resistors 5 and are part of a fluid circuit 7 that is in fluid communication with the ink flow openings 13 of the cartridge 37. Therefore, the ejection chambers 6 are said to be in fluid communication with the ink flow openings 13. Ink from the ink flow openings 13 flows through the fluid circuit 7 to the ejection chambers 6. The fluid circuit 7 is patterned on a suitable polymer layer called a barrier layer 39. A nozzle plate 8 is disposed on the barrier layer 39 and closes the top end of the microfluidic device 2. The nozzle plate 8 also covers the ejection chambers 6. The nozzle plate 8 includes an ejection nozzle 9 for each ejection chamber 6. The ejection nozzle 9 is used to eject ink from the ejection chambers 6. Specifically, a sudden current pulse can be applied on demand through the resistors 5, causing rapid vaporization of a thin layer of ink. When the vapor pressure is high, the vapor bubble expands, drawing the ink upward from the discharge nozzle 9 and ejecting an ink droplet. After ejection, new ink is collected from the ink reservoir 10 and replenished into the discharge chamber 6 and the discharge nozzle 9 again.

[0036]

[0051] As previously mentioned, the inkjet printhead 1 uses a backpressure system to help control ink flow. In this embodiment, as shown in FIGS. 6a and 6b, a porous member 14 (e.g., open-cell foam) and / or a fibrous member can be inserted into the ink reservoir 10 to generate a negative pressure in the liquid contained within the ink reservoir 10 through a network of pores or a capillary effect between the fibers. However, other methods can be used to generate an appropriate backpressure in the liquid. For example, a blister having an opening in fluid communication with a pipe and an ejection chamber can be used, with the blister shell mechanically biased outward via a metal spring or some other elastic element. The blister, separate from the opening for communication with the pipe, is fluidly isolated from the external environment. The elastic components must be carefully calibrated to provide the appropriate backpressure throughout the life of the inkjet printhead.

[0037]

[0052] As shown in FIGS. 6a and 6b , the cartridge 37 further includes a cartridge lid 15 for covering the opening 38 of the cartridge body 4. Specifically, the peripheral seal frame 22 of the cartridge lid 15 can be joined to the cartridge body 4 so that the opening 38 of the cartridge body 4 is covered by the cartridge lid 15. In order to eliminate or at least mitigate the effects of imbalance between the pressure inside the cartridge 37 and the pressure outside the cartridge 37, a specific ink expansion volume or expansion space 25 is formed in the cartridge lid 15. The purpose is to prevent ink from reaching an area outside the cartridge 37 in a short journey by direct communication. On the contrary, the ink is forced to pass through a longer expansion space 25, in particular a circuitous expansion path or expansion circuit, before reaching the vent 17, thereby attenuating the severity of possible ejection and providing an internal expansion volume or internal expansion space 25 that can accommodate all or most of the ink displaced due to the pressure imbalance.

[0038]

[0053] As shown in Figures 6a, 6b, and 8 to 11, the cartridge lid 15 includes an outer lid member 40 and an inner lid member 27 attached to the outer lid member 40. Terms describing positional relationships, such as "outside," "inside," "upper side," and "lower side," are used herein to describe the cartridge lid 15 covering the opening 38 of the cartridge body 4. The outer lid member 40 is provided with an ink fill hole 16 for filling the ink reservoir 10 of the cartridge 37 with ink and a vent hole 17 for communicating the ink reservoir 10 of the cartridge 37 with the external environment. The vent hole 17 is located at one end of a shallow serpentine vent channel 18 molded in the outer surface of the outer lid member 40. The ink fill hole 16 is large enough to allow an ink filling tool, such as a needle, to pass through to fill the ink reservoir 10 with ink. The inner lid member 27 is provided inside the outer lid member 40 and overlaps the vent hole 17. It can be seen that the inner lid member 27 does not overlap the ink fill hole 16 and therefore does not affect the filling of ink through the ink fill hole 16. An expansion space 25 having an inlet 26 is formed between the outer lid member 40 and the inner lid member 27. The expansion space 25 is in communication with the external environment via the vent hole 17. The inlet 26 may be provided on the opposite side of the vent hole 17, for example, the inlet 26 may be provided in the inner lid member 27. Alternatively, the inlet 26 may be provided between the outer lid member 40 and the inner lid member 27. When the cartridge lid 15 covers the opening 38 of the cartridge body 4, the inlet 26 allows ink from the ink reservoir 10 to flow into the expansion space 25, and the vent hole 17 connects the expansion space 25 to the external environment. The inner surface (e.g., lower surface) of the outer lid member 40 acts as a ceiling of the expansion space 25, while the outer surface (e.g., upper surface) of the inner lid member 27 acts as a floor of the expansion space 25. In one possible embodiment, the inner lid member 27 is parallel to the outer lid member 40. The inner lid member 27 may be removably attached to the outer lid member 40. The inner lid member 27 may also be joined to the outer lid member 40 using any suitable adhesive or glue, ultrasonic welding, or any other method known in the art. Furthermore, the inner lid member 27 may be realized by molding as the rest of the cartridge lid 15, but this would make the manufacturing process very complicated and expensive.

[0039]

[0054] Preferably, expansion space 25 is a circuitous expansion circuit. The circuitous shape of expansion space 25 increases both the damping effect and the available volume through which it must pass. A circuitous expansion circuit requires that ink entering expansion space 25 from inlet 26 must travel a longer path and take more time before being ejected from vent 17.

[0040]

[0055] One type of circuitous expansion circuit can be thought of as a series of expansion chambers connected via narrow connecting passages. Specifically, as shown in Figures 8-13, the expansion space 25 can include multiple expansion chambers fluidly connected via narrow connecting passages. For example, referring to Figure 14, expansion chambers 31 and 32 are connected via a narrow connecting passage 33. The abrupt changes in width along the expansion circuit due to the multiple narrow connecting passages 33 contribute to flow attenuation.

[0041]

[0056] The expansion chamber may be surrounded by chamber wall 24 and by a perimeter reinforcing frame 41, which in turn is connected to outer and inner lid members 40 and 27. The outer and inner lid members 40 and 27 may be connected to chamber wall 24 and perimeter reinforcing frame 41 without affecting perimeter seal frame 22. This can be achieved by modifying the rib configuration of an existing cartridge lid (one of which is shown in FIG. 4 ) by adding additional parts or by changing the length and position of existing ribs 23 to form the chamber wall 24 of the expansion chamber. The chamber wall 24 and perimeter reinforcing frame 41 may be connected to outer and inner lid members 40 and 27 using any suitable adhesive or bonding, ultrasonic welding, or any other method known in the art.

[0042]

[0057] Optionally, the expansion space 25 may contain some porous material. For example, in another embodiment shown in Figures 12 and 13, a portion of the expansion space 25 in the cartridge lid 15 may even contain some porous material 28 to increase damping of the ink flow momentum without compromising fluid communication with the outside. The porous material 28 may be contained in only a single expansion chamber, or in multiple expansion chambers, or in all expansion chambers.

[0043]

[0058] In yet another embodiment, some chamber walls of the expansion chamber have curved profiles rather than straight, as shown in Figure 14. In this embodiment, the chamber walls include two curved walls 29 surrounding the vent hole 17. The two curved walls 29 are spaced apart so as to form two narrow communication passages 30 for the ink.

[0044]

[0059] The narrow passage can be achieved in various ways, as shown in FIG. 15 . A cross section of the cartridge lid 15 corresponding to the chamber wall 24 illustrates various possible ways to achieve the narrow passage. For example, two adjacent chamber walls 24 are spaced apart from each other, and the narrow passage 34 is formed by a gap between the two adjacent chamber walls 24. In this case, the gap extends from the outer lid member 40 to the inner lid member 27. In another example, the narrow passage 35 is formed as a gap in the chamber wall 24. The gap does not reach the outer lid member 40, but there is a riser connecting both sides of the gap, resulting in a shallow gap. In yet another example, the narrow passage 36 is formed completely in the chamber wall 24, forming a hole that runs through the entire chamber wall 24. While the first two variations can be easily achieved using standard molding processes, the latter requires a more complex manufacturing process. In any case, all of them can be advantageously employed.

[0045]

[0060] The described embodiments are merely examples of the concept of the present invention. Detailed features of the expansion space or expansion circuit can be appropriately changed or integrated according to different solutions without departing from the spirit and scope of the present invention. The expansion space built into the cartridge lid for the cartridge of the inkjet printhead effectively addresses the problem caused by the pressure imbalance between the inside and outside of the ink reservoir, fixes the logistics drawbacks, and enables the inkjet printhead to be used correctly at different altitudes.

[0046]

[0061] The various technical features described above can be combined in any manner, and although not all possible combinations of the various technical features are described, all combinations of these technical features, unless inconsistent, should be considered to be within the scope described herein.

[0047]

[0062] Although the present invention has been described in conjunction with the embodiments, those skilled in the art will recognize that the above description and drawings are merely illustrative and not restrictive, and the present invention is not limited to the disclosed embodiments. Various modifications and variations are possible without departing from the concept of the present invention. [Explanation of symbols]

[0048] 1 inkjet printhead 2. Microfluidic Device 3 contact pads 4 Cartridge body 5 resistor 6 Discharge Chamber 7 Fluid circuit 8 Nozzle Plate 9 Discharge nozzle 10 Ink reservoir 11 Pipe 12 Filtration device 13 Ink flow opening 14 Porous materials 15 Cartridge lid 16 Ink filling hole 17 Ventilation holes 18 shallow serpentine ventilation channels 19 Adhesive Labels 20 Ventilation outlet 21 Ink Flow 22 Periphery seal frame 23 Ribs 24 Chamber wall 25 Expanded Space 26 Entrance 27 Inner cover member 28 Porous materials 29 Curved wall 30 Narrow Passage 31 Expansion Chamber 32 Expansion Chamber 33 Narrow Passage 34 Narrow Passage 35 Narrow Passage 36 Narrow Passage 37 Cartridge 38 Aperture 39 Barrier Layer 40 Outer cover member 41 Periphery reinforcement frame

Claims

1. an outer lid member provided with an ink filling hole and an air vent; an inner lid member attached to the outer lid member and overlapping the ventilation hole; Equipped with an expansion space is formed between the outer lid member and the inner lid member, the expansion space has an inlet, and when the cartridge lid covers the opening of the cartridge body, ink can flow into the expansion space from an ink reservoir formed in the cartridge body through the inlet, and the expansion space is in communication with an external environment through the vent hole; the expansion space contains a porous material; Cartridge lid.

2. The cartridge lid of claim 1 , wherein the expansion space is a circuitous expansion circuit.

3. 3. The cartridge lid according to claim 1, wherein the expansion space comprises a plurality of expansion chambers fluidly connected via narrow communication passages, and each expansion chamber is surrounded by a chamber wall connected to the outer lid member and the inner lid member.

4. The cartridge lid of claim 3 , wherein the chamber wall comprises two curved walls surrounding the vent hole.

5. 5. A cartridge lid according to claim 3 or 4, wherein two adjacent chamber walls are spaced apart to form said narrow communication passage.

6. The cartridge lid according to any one of claims 3 to 5, wherein the narrow communication passage is formed in the chamber wall.

7. The cartridge lid according to any one of claims 1 to 6, wherein the inner lid member is parallel to the outer lid member.

8. a cartridge body having an opening and an ink flow opening and an ink reservoir formed therein for containing ink; a cartridge lid according to any one of claims 1 to 7 for covering the opening; A cartridge comprising:

9. The cartridge of claim 8 , wherein the cartridge comprises a porous and / or fibrous member inserted within the ink reservoir.

10. An inkjet printhead comprising the cartridge according to claim 8 or 9.

11. the inkjet printhead is a thermal inkjet printhead having a microfluidic device attached to the cartridge, the microfluidic device comprising: a plurality of resistors; a plurality of ejection chambers disposed above the plurality of resistors and in fluid communication with the ink flow opening; a nozzle plate covering the plurality of ejection chambers and provided with a plurality of ejection nozzles for ejecting ink from the plurality of ejection chambers; The inkjet printhead of claim 10 comprising:

12. An inkjet printer comprising the inkjet printhead according to claim 10 or 11.

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