Cartridge, ink jet print head and ink jet printer

Abstract

This invention relates to the field of inkjet printing technology. When the external pressure changes significantly after ink filling, the cartridge experiences ink leakage, and the cartridge's ink fountain communicates with the external environment through a vent. This invention provides a cartridge (37) comprising: a cartridge body (4); a cartridge cover (15); and a flexible member (101) located between the cartridge cover (15) and an opening (38) of the cartridge body (4). When the cartridge cover (15) is installed on the cartridge body (4), a rib (23) on the cartridge cover (15) abuts against the flexible member (101) to form a sealing contact between the two, thereby forming an expansion space (25) capable of accommodating all or most of the ink discharged from the ink fountain. This invention also provides an inkjet printhead and an inkjet printer.

Description

[Technical Field]

[0001] This invention relates to the field of inkjet printing technology, and more particularly, to preventing ink from leaking from the vent to the outside of the cartridge due to transportation and / or use of the inkjet printhead at a different altitude than the factory, and more particularly, to the cartridge, the inkjet printhead, and the inkjet printer. [Previous Technology]

[0002] As shown in Figures 1a, 1b, and 2, the cartridge 37 of the inkjet printhead includes a cartridge body 4 and a cartridge cover 15 for covering an opening 38 of the cartridge body 4. An ink fountain 10 for containing ink is formed within the cartridge body 4. The cartridge body 4 further includes an ink flow orifice 13 communicating between the ink fountain 10 and the ejection chamber of the inkjet printhead, wherein the ink flow orifice 13 is connected to the ink fountain 10 via a filter 12 and a conduit 11.

[0003] Precise control of the ink flow through the nozzles of the inkjet printhead's ejection chamber is essential, as it is one of the fundamental prerequisites for achieving high-quality printing with an inkjet printer. One system that helps provide this control over ink flow is a back pressure system, which creates a slight negative pressure in the liquid within the ink fountain of the cartridge housed in the inkjet printhead. This negative pressure in the liquid prevents accidental ink leakage. Otherwise, such leakage could occur when the inkjet printhead is idle or when the cartridge experiences a sudden acceleration during processing.

[0004] As shown in Figures 1a, 1b and 2, a possible back pressure system known in this art employs a porous component 14 (e.g., open-cell foam), a fibrous component, or a combination of both, inserted into the ink fountain 10 of the cartridge 37 to generate a negative pressure in the liquid contained within the ink fountain 10, which is generated by the capillary effect between the porous network or fibers, as described in patent EP 3302983 B1.

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

[0006] To provide suitable communication with the external environment, the cartridge cover 15 is typically provided with a vent 17 in addition to the ink filling hole 16. Specifically, as shown in Figures 1a, 1b, 2, 3a, and 3b, the cartridge cover 15 is provided with: an ink filling hole 16 through which the needle passes through most of the path across the porous member 14 to fill the ink fountain 10 with ink; and a vent 17 for communicating the ink fountain 10 with the external environment. The vent 17 is located at one end of a shallow serpentine venting channel 18 molded in the outer surface of the cartridge cover 15. The ink filling hole 16 is relatively large and is sealed after filling with an adhesive label 19 or a stopper (not shown) to prevent excessive ink evaporation. The adhesive label 19 overlaps not only with the ink filling hole 16 but also with the vent 17. The adhesive label 19 is sealed on top of most of the shallow serpentine venting channel 18, acting as a top plate surface. The vent 20, located at the very end of the shallow serpentine venting channel 18, remains uncovered, allowing the ink fountain 10 to communicate with the external environment. The small cross-section and suitable length of the shallow serpentine venting channel 18 maintain a low evaporation rate while preserving pressure balance between the inside and outside of the ink fountain 10, even during printing. Alternatively, two separate labels (not shown) can be appropriately used for the ink filling hole 16 and the vent 17, respectively. As shown in Figure 4, in addition to the ink filling hole 16 and the vent 17, the inner surface of the cartridge cover 15 is typically provided with a peripheral sealing frame 22 suitable for ultrasonic engagement with the cartridge body 4, a plurality of ribs 23, and an additional outer peripheral reinforcing frame 41 designed to adequately reinforce the cartridge cover 15, thereby preventing any deformation or breakage of the cartridge cover 15. Typically, these ribs 23 and the outer peripheral reinforcing frame 41 are formed simultaneously during the molding process of the cartridge cover 15.

[0007] The ink filled into the ink fountain 10 permeates most of the porous member 14. Capillary action prevents the ink from flowing out of the porous member 14. However, the ink has a certain amount of internal fluidity in the porous member 14, especially when the porous member 14 is a fibrous member that readily allows ink to move along the fiber direction. Therefore, the processing of an ink-filled inkjet printhead can result in some air being trapped in the porous member 14. This trapped air may even be surrounded by ink. Some additional air trapping may even occur in the conduit 11 due to possible operational errors or a lack of airtight seal between the ink filling orifice 16 and the needle during the ink filling stage. In short, there is a possibility that some air islands remain trapped in the ink within the inkjet printhead.

[0008] After filling, atmospheric pressure surrounding the inkjet printhead also exists in the inkless portion of the ink fountain 10, while in the liquid contained in the inkjet printhead, the resulting pressure is caused by atmospheric pressure, increases due to the hydrostatic pressure of the liquid column, and decreases due to the capillary pressure of the porous member 14. The capillary action of the porous member 14 is carefully designed to provide a lower pressure relative to the external environment for the liquid contained in the ink fountain, and this capillary action depends on the pore size, the surface tension of the ink, and the wettability of the porous member material.

[0009] Before the inkjet printhead is ready for shipment, the nozzles are sealed with appropriate tape to prevent ink evaporation and protect the nozzles from particulate contamination or mechanical scratches. Finally, the inkjet printhead is placed in a plastic cup and heat-sealed with a double-layered plastic-aluminum packaging cap. Thus, the inkjet printhead is enclosed in a sealed container with the same internal pressure as atmospheric pressure at the factory.

[0010] However, during the transport of inkjet printheads or when they are used in high-altitude areas, the sealed container may experience significant pressure changes. For example, in air transport, the cargo hold may be under low pressure during flight. Also, the final destination of the inkjet printhead may be under environmental pressures significantly different from the factory environment due to varying altitudes. These changes in environmental pressure within the sealed container can lead to an imbalance between the internal pressure of the sealed container and the ambient pressure. This imbalanced internal pressure pulls the packaging lid outwards, causing the internal pressure of the sealed container to decrease relative to the original pressure in the factory.

[0011] Since the ink fountain is connected to the area outside the cartridge via the vent, if the environment is at a pressure lower than the factory pressure, the air trapped in the porous component may expand and discharge ink. When the cartridge is in a sealed container or when the end user opens the packaging cover, ink may leak out from the vent.

[0012] Seal the vent with an additional label or removable stopper only prevents ink leakage within the sealed cup, but it will not work if the final destination pressure is significantly lower than the factory pressure: removing the additional label or stopper will cause a sudden pressure imbalance inside, causing ink to spray out of the vent. This phenomenon may also occur if no air is trapped within the porous component. In any case, sudden disturbances in the internal pressure of the sealed container can easily cause ink to spray out of the vent because the communication between the liquid surface in the ink fountain and the outside is short and the ink can flow almost directly outward.

[0013] Figure 2 schematically depicts the ink ejection from the vent 17. The relative positions of the ink fountain 10 and the cartridge cover 15 are shown in an exploded view, where a sudden flow of ink 21 caused by pressure imbalance is schematically indicated by arrows. The ink rapidly covers a short, direct path toward the ink filling hole 16 and the vent 17 toward the cartridge cover 5. The ink filling hole 16 is sealed by an adhesive label 19 (Figure 3b), which also overlaps with the vent 17 and most of the shallow serpentine vent channel 18, leaving a vent outlet 20 communicating with the outside. The shallow serpentine vent channel 18 below the adhesive label 19 has a very small volume and can be rapidly filled with ink, resulting in ink ejection from the vent outlet 20 located at the very end of the shallow serpentine vent channel 18. [Summary of the Invention]

[0014] In order to solve the above technical problems, the solution of the present invention consists of providing a cartridge having an expansion space connected to a vent hole in order to collect any possible ink flow caused by the imbalance between the pressure inside the ink fountain and the ambient pressure outside the ink fountain due to changes in ambient pressure, thereby preventing ink leakage to the outside of the cartridge.

[0015] In a first embodiment of the present invention, a cartridge is provided. The cartridge includes: a cartridge body having an opening and an ink flow orifice, wherein an ink fountain for receiving ink is formed within the cartridge body; a cartridge cover for covering the opening, wherein the cartridge cover is provided with an ink filling hole and a vent hole, and ribs are provided on its inner surface; and a flexible member disposed between the cartridge cover and the opening and overlapping the vent hole but not the ink filling hole, wherein when the cartridge cover is installed on the cartridge body and covers the opening, the ribs abut against the flexible member to form a sealing contact between the ribs and the flexible member and to form an expansion space between the cartridge cover and the flexible member, wherein the expansion space has an inlet through which ink can flow from the ink fountain into the expansion space, and the expansion space communicates with the external environment through the vent hole.

[0016] The cartridge of the present invention prevents ink from reaching the area outside the cartridge 37 during a short stroke via a direct connection. Instead, the ink is forced through a longer expansion space, thereby suppressing the potential intensity of ejection and providing an internal expansion volume or internal expansion space capable of accommodating all or most of the ink discharged from the ink fountain due to pressure imbalance. Furthermore, since the flexible component is slightly flexible and fits well with the ribs on the cartridge cover, the expansion space is formed only by the sealing contact between the ribs on the cartridge cover and the flexible component, without requiring a true connection between the cartridge cover and the flexible component. Therefore, the manufacturing process is simpler, easier to introduce into the production line, and cost-effective.

[0017] Preferably, the cartridge includes a porous component and / or a fiber component inserted into the ink fountain, and the size of the flexible component is set to be precisely inserted into the cartridge body, just above the porous component or the fiber component and having an open space corresponding to the ink filling hole.

[0018] With this implementation, after inserting the porous component and / or fiber component, the soft component is simply inserted into the cartridge body and placed on the cartridge body without any alignment. Subsequently, the cartridge cover can be installed onto the cartridge body. During installation, the ribs on the cartridge cover are subjected to a certain pressure, which is partially transferred to the soft component, thereby achieving a sealing contact. Furthermore, even during cartridge handling, the soft component cannot slip and remains in its stable position, thus ensuring proper contact with the ribs on the overlying cartridge cover.

[0019] Preferably, the soft component has two spaced-apart wings at one end to form an open space extending to the peripheral edge of the soft component. This implementation simplifies ink filling of the cartridge.

[0020] Preferably, the soft component is provided with a through hole aligned with the ink filling hole.

[0021] Preferably, the soft component is made of rubber.

[0022] Preferably, the flexible member is a plate-shaped member with a thickness of 1 mm to 2 mm. The thickness of 1 mm to 2 mm is sufficient to form an expansion space between the cartridge cover and the flexible member. In addition, it can even compensate for small irregularities in the rib edges introduced during the cover molding process.

[0023] Preferably, the expansion space contains a porous material. The porous material can enhance the suppression of the intensity of ink flow without impairing fluid communication with the outside.

[0024] Preferably, the expansion space is a circuitous expansion loop. Giving the expansion space a circuitous shape will enhance the inhibition effect and increase the available volume that needs to be passed through. The circuitous expansion loop forces the ink flowing from the inlet into the expansion space to take a longer flow path and more time before being ejected from the vent.

[0025] Preferably, the expansion space comprises a plurality of expansion chambers fluidly connected via narrow communication passages, and each expansion chamber is surrounded by ribs connected to the cartridge cover and abutting against the flexible member. Due to the plurality of narrow communication passages, the abrupt change in width along the expansion loop helps to suppress flow.

[0026] Preferably, the ribs include two curved ribs surrounding the vent.

[0027] Preferably, two adjacent ribs are spaced apart from each other to form a narrow connecting passage.

[0028] Preferably, the narrow connecting passage is formed in the ribs.

[0029] In a second embodiment of the present invention, an inkjet printhead is provided. The inkjet printhead includes the aforementioned cartridge.

[0030] Preferably, the inkjet printhead is a thermal inkjet printhead, the thermal inkjet printhead including a microjet device attached to the cartridge, wherein the microjet device includes: a plurality of resistors; a plurality of ejection chambers disposed above the resistors and in fluid communication with ink flow orifices; and a nozzle plate covering the ejection chambers and provided with nozzles for ejecting ink from the ejection chambers.

[0031] In a third embodiment of the present invention, an inkjet printer is provided. The inkjet printer includes the above-described inkjet printhead.

Implementation Method

[0049] To make the above and other features and advantages of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments of the present invention are illustrative and not intended to be restrictive.

[0050] The present invention provides a cartridge, an inkjet printhead, and an inkjet printer. Figure 5 shows a perspective view of an inkjet printhead 1 according to an embodiment of the present invention. In this embodiment, the inkjet printhead 1 is a thermal inkjet printhead, such as a bubble jet inkjet printhead. In other embodiments, the inkjet printhead 1 may also be an electro-inkjet printhead.

[0051] The inkjet printhead 1 includes one or more cartridges 37. Each cartridge 37 can hold ink of a different color. Figures 6a and 6b show exploded views of the cartridges of the inkjet printhead in Figure 5. As shown in Figures 6a and 6b, the cartridge 37 includes a cartridge body 4, typically made of plastic. The cartridge body 4 has an opening 38 and an ink flow orifice 13. An ink fountain 10 for holding ink is formed within the cartridge body 4. A filter device 12 is disposed between the ink flow orifice 13 and the ink fountain 10. In this embodiment, the filter device 12 is a screen filter. Optionally, the filter device 12 communicates with the ink flow orifice 13 via a conduit 11 (e.g., a riser), the top of which has the filter device 12 at its boundary with the ink fountain 10 and terminates at the ink flow orifice 13 at the other end.

[0052] As shown in Figure 5, the inkjet printhead 1 further includes a microjet device 2 attached to the cartridge 37. For example, the microjet device 2 is adhered to the cartridge body 4 of the cartridge 37 via sealant, which provides mechanical strength and airtightness to the joint between the microjet device 2 and the cartridge 37. The microjet device 2 is in fluid communication with the ink flow orifice 13 of the cartridge 37, allowing ink contained in the ink fountain 10 of the cartridge 37 to flow to the microjet device 2 through the ink flow orifice 13. The microjet device 2 is electrically actuated via the contact pad 3.

[0053] Figure 7 shows a partial cross-sectional schematic diagram of the microjet device of the inkjet printhead in Figure 5. As shown in Figure 7, the microjet device 2 includes a plurality of ejection chambers 6 and a plurality of resistors 5 corresponding to the plurality of ejection chambers 6. The ejection chambers 6 are disposed above the resistors 5 and are part of a jet circuit 7 in fluid communication with the ink flow orifices 13 of the cartridge 37. Therefore, it can be said that the ejection chambers 6 are in fluid communication with the ink flow orifices 13. Ink from the ink flow orifices 13 flows in the jet circuit 7 and reaches the ejection chambers 6. The jet circuit 7 is patterned in a suitable polymer layer called a barrier layer 39. A nozzle plate 8 is disposed on the barrier layer 39 and closes the microjet device 2 on top. The nozzle plate 8 also covers the ejection chambers 6. The nozzle plate 8 is provided with nozzles 9 for each ejection chamber 6. The nozzles 9 are used to eject ink from the ejection chambers 6. Specifically, a sudden current pulse can be applied via the resistors 5 as needed, resulting in rapid evaporation of the ink thin layer. The high vapor pressure causes the vapor bubbles to expand, which expels the ink above from nozzle 9, thus creating ink droplet ejection. After ejection, new ink is drawn from ink fountain 10 to refill ejection chamber 6 and nozzle 9.

[0054] As described above, a back pressure system is used in the inkjet printhead 1 to help provide control over ink flow. In this embodiment, as shown in Figures 6a and 6b, a porous member 14 (e.g., open-cell foam) and / or a fiber member can be inserted into the ink fountain 10 to generate a negative pressure in the liquid contained within the ink fountain 10, which is generated by the capillary effect between the porous network or fibers. However, other methods can be used to generate suitable back pressure in the liquid. For example, a bubble cap with an opening that is in fluid communication with the conduit and the jet chamber can be used; and the bubble cap shell is mechanically biased outward via a metal spring or some other elastic element. Except for the opening that communicates with the conduit, the bubble cap is fluidly isolated from the external environment. The elastic components must be carefully calibrated to provide suitable back pressure throughout the life of the inkjet printhead.

[0055] As shown in Figures 6a and 6b, the cartridge 37 further includes a cartridge cover 15 for covering the opening 38 of the cartridge body 4. The cartridge cover 15 can be detachably mounted to the cartridge body 4. The cartridge cover 15 can also be permanently mounted to the cartridge body 4, or in other words, combined with the cartridge body 4, for example by adhesive, ultrasonic welding, or any other suitable method. Specifically, as shown in Figures 8 and 9, which respectively show a perspective view and a bottom view of the cartridge cover according to an embodiment of the present invention, the peripheral sealing frame 22 of the cartridge cover 15 can be combined with the cartridge body 4 so that the opening 38 of the cartridge body 4 is covered by the cartridge cover 15. As shown in Figures 6a, 6b, 8, and 9, the cartridge cover 15 is provided with an ink filling hole 16 and a vent hole 17. The filling hole 16 is used to fill the ink fountain 10 with ink. The vent hole 17 is used to connect the ink fountain 10 to the external environment. A vent 17 is located at one end of a shallow serpentine vent channel 18, which is molded into the outer surface of the cartridge cover 15. An ink filling hole 16 is relatively large, through which an ink filling tool (such as a needle) can pass to fill the ink fountain 10. Furthermore, the cartridge cover 15 has ribs 23 on its inner surface. It should be noted that terms describing positional relationships, such as "external," "internal," "upper," and "lower," are used herein relative to the case where the cartridge cover 15 covers the opening 38 of the cartridge body 4. On the one hand, the ribs 23 are designed to adequately reinforce the cartridge cover 15, thereby preventing any deformation or breakage of the cartridge cover 15; on the other hand, the ribs 23 form the chamber walls of the expansion space 25, which will be described in detail below.

[0056] To eliminate or at least mitigate the effects of the pressure imbalance between the inside and outside of the cartridge 37, a specific ink expansion volume or expansion space 25 is created. As shown in Figures 6a and 6b, the cartridge 37 further includes a flexible member 101 disposed between the cartridge cover 15 and the opening 38 of the cartridge body 4 and overlapping the vent 17. It is understood that the flexible member 101 does not overlap with the ink filling hole 16 to avoid affecting ink filling via the ink filling hole 16. When the cartridge cover 15 is mounted to the cartridge body 4 and covers the opening 38 of the cartridge body 4, a rib 23 disposed on the inner surface of the cartridge cover 15 abuts against the flexible member 101 to form a sealing contact between the rib 23 and the flexible member 101 and to form the expansion space 25 between the cartridge cover 15 and the flexible member 101. As shown in Figures 8 and 9, the expansion space 25 has an inlet 26 through which ink can flow from the ink fountain 10 into the expansion space 25, and the expansion space 25 communicates with the external environment via a vent 17. The inlet 26 may be positioned away from the vent 17. Depending on the situation, the inlet 26 may be located within the flexible member 101. Alternatively, the inlet 26 may be located between the cartridge cover 15 and the flexible member 101. When the cartridge cover 15 covers the opening 38 of the cartridge body 4, the inlet 26 allows ink from the ink fountain 10 to flow into the expansion space 25, and the vent 17 communicates the expansion space 25 with the external environment. The inner surface (e.g., the lower surface) of the cartridge cover 15 acts as the top plate of the expansion space 25, while the outer surface (e.g., the upper surface) of the flexible member 101 acts as the bottom plate of the expansion space 25. In one possible embodiment, the flexible member 101 is parallel to the cartridge cover 15.

[0057] The purpose of forming the expansion space 25 is to prevent ink from reaching the area outside the cartridge 37 in a short distance via a direct connection. Instead, the ink is forced through a longer expansion space 25, specifically a detour expansion path or expansion loop, before reaching the vent 17, thereby suppressing the possible intensity of ejection and providing an internal expansion volume or internal expansion space 25 that can accommodate all or most of the ink discharged from the ink fountain due to pressure imbalance.

[0058] The flexible component 101 is made of a soft material such as rubber (especially silicone rubber). Figures 10 and 11 show a perspective view and a bottom view of the flexible component according to an embodiment of the invention, respectively. As shown in Figures 10 and 11, the flexible component 101 may be a plate-shaped component with sufficient thickness to contact the ribs 23 on the cartridge cover 15 with a certain pressure once the cartridge cover 15 has been installed (e.g., ultrasonically bonded) to the cartridge body 4. Because the flexible component 101 is slightly flexible and can match well with the ribs 23 on the cartridge cover 15, the mechanical interference and flexibility of the flexible component 101 can provide a good sealing contact without the need for any adhesives or glues to attach the flexible component 101 to the cartridge cover 15, i.e., no actual adhesion is required between the cartridge cover 15 and the flexible component 101. Therefore, the manufacturing process is simpler, easier to introduce into the production line, and cost-effective. Typically, the thickness of the plate-shaped soft member 101 is 1 mm to 2 mm, which is sufficient to form an expansion space 25 together with the cartridge cover 15, and can even compensate for small irregularities in the rib edges introduced during the cover molding process.

[0059] In principle, the soft component 101 only needs to overlap with a portion of the cartridge cover 15 that includes the vent 17 (e.g., the right half of the cartridge cover 15 shown in Figure 8); however, since the soft component 101 is not attached to the cartridge cover 15, the soft component 101 can slide back and forth during the handling of the cartridge in the manufacturing process, which carries the risk that part of the expansion space 25 may not be completely closed.

[0060] In a preferred embodiment, the shape of the soft member 101 is set as shown in Figures 10 and 11. The size of the soft member 101 is set to precisely fit into the cartridge body 4, just above the porous member 14 or the fiber member. The position of the soft member 101 above the porous member 14 or the fiber member is self-adjusting within the cartridge body 4. In other words, the opening 38 of the cartridge body 4 can precisely accommodate the soft member 101 just above the porous member 14 or the fiber member. It is worth emphasizing that the porous member 14 or the fiber member should have a certain degree of rigidity in order to effectively contrast the pressure applied by the soft member 101. For example, the fiber member is a piece of fiber that is quite stiff when compressed along the fiber direction. In addition, the compressed foam may also have sufficient rigidity.

[0061] The flexible component 101 is provided with an open space 103 corresponding to the ink filling hole 16. The inlet 26 of the expansion space 25 can communicate with the ink fountain 10 via the open space 103. In this way, after inserting the porous component 14 and / or the fiber component, the flexible component 101 can be simply inserted into the cartridge body 4 and placed on the cartridge body 4 without any alignment. Subsequently, the cartridge cover 15 can be installed onto the cartridge body 4. During installation, the ribs 23 on the cartridge cover 15 are subjected to a certain pressure, which is partially transferred to the flexible component 101, thereby achieving a sealing contact. Furthermore, even during cartridge handling, the flexible component 101 cannot slip and remains in its stable position, thereby ensuring proper contact with the ribs 23 on the overlying cartridge cover 15.

[0062] Specifically, as shown in Figures 10 and 11, the soft member 101 has two spaced-apart wings 102 at one end. The two wings 102 in the soft member 101 serve the following purposes: to form the aforementioned open space 103 to allow the ink fountain 10 to be filled through the ink filling hole 16 of the cartridge cover 15 without any obstruction, while providing positional stability of the soft member 101 above the porous member 14 or fiber member within the cartridge body 4. It can be clearly seen that the open space 103 extends to the peripheral edge of the soft member 101. In fact, the open space 103 does not need to extend all the way to the peripheral edge of the soft member 101, and a simple through hole provided in the soft member 101 and aligned with the overlying ink filling hole 16 would be sufficient to allow the ink fountain 10 to be filled through the ink filling hole 16 of the cartridge cover 15 without any obstruction. However, the applicant found that the ink filling of the ink fountain 10 becomes simpler when the wing solution is adopted.

[0063] Preferably, the expansion space 25 is a circuitous expansion loop. Giving the expansion space 25 a circuitous shape will enhance the inhibition effect and increase the available volume that needs to be passed through. The circuitous expansion loop forces the ink flowing from the inlet 26 into the expansion space 25 to take a longer flow path and more time before being ejected from the vent 17.

[0064] A circuitous expansion loop can be considered as a series of expansion chambers connected via narrow connecting passages. Specifically, as shown in Figures 8 and 9, the expansion space 25 may contain a plurality of expansion chambers fluidly connected via narrow connecting passages. For example, referring to Figure 14, expansion chambers 31 and 32 are connected via narrow connecting passages 33. Due to the plurality of narrow connecting passages 33, the abrupt change in width along the expansion loop helps to suppress flow.

[0065] The expansion chamber may be surrounded by chamber walls (i.e., ribs 23), which are then connected to the cartridge cover 15 and abut against the flexible member 101. The expansion chamber may also be surrounded by an outer peripheral reinforcing frame 41, which is then connected to the cartridge cover 15 and abuts against the flexible member 101. The outer peripheral reinforcing frame 41 protrudes beyond the peripheral sealing frame 22. The chamber walls of the expansion chamber can be created by modifying the rib design of the existing cartridge cover (one of which is shown in Figure 4) by adding additional components or modifying the length and position of the existing ribs 23. The chamber walls and the outer peripheral reinforcing frame 41 can be connected to the cartridge cover 15 using a suitable glue or adhesive, ultrasonic welding, or any other method known in the art.

[0066] Depending on the situation, 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 may even contain some porous material 28 to enhance the suppression of the intensity of ink flow without impairing fluid communication with the outside. The porous material 28 may be contained in only one expansion chamber, or it may be contained in multiple expansion chambers, or even in all expansion chambers.

[0067] In another embodiment, some of the chamber walls of the expansion chamber have a curved profile instead of a straight profile, as shown in Figure 14. In this embodiment, the chamber walls include two curved walls 29 surrounding the vent 17. The two curved walls 29 are spaced apart from each other to form two narrow communication passages 30 for ink.

[0068] Narrow communication passages can be obtained in various ways, as shown in Figure 15. A cross-section of the cartridge cover 15 illustrates various possible ways of obtaining narrow communication passages. For example, two adjacent chamber walls are spaced apart from each other, and a narrow communication passage 34 is created by the gap between the two adjacent chamber walls, where the gap extends from the cartridge cover 15 to the flexible member 101. Another example is a narrow communication passage 35 configured as a gap, located within the chamber wall, and this gap does not reach the cartridge cover 15, but there are vertical walls connecting the two sides of the gap, thus creating a shallow gap. Yet another example is a narrow communication passage 36 completely located within the chamber wall and configured as a through-hole. The first two variations can be easily obtained by standard molding processes, while the latter requires a more complex manufacturing process. In any case, all of them can be advantageously employed.

[0069] The described embodiments are merely examples of the concepts of the present invention. Without departing from the spirit and scope of the invention, the detailed features of the expansion space or expansion circuit may be appropriately varied or combined according to different solutions. The expansion space integrated into the cartridge cover of the cartridge for the inkjet printhead effectively solves the problem caused by the pressure imbalance between the inside and outside of the ink fountain, thereby resolving logistical drawbacks and enabling the inkjet printhead to be used correctly at different altitudes.

[0070] The above-mentioned technical features can be combined in any way. Although not all possible combinations of the various technical features are described, all combinations of these technical features should be considered within the scope described in this specification, provided that they do not conflict.

[0071] Although the present invention has been described in conjunction with embodiments, those skilled in the art should understand that the above description and drawings are illustrative only 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 invention. [Simplified Explanation of the Diagram]

[0032] Non-limiting and non-exhaustive embodiments of the present invention will be described by way of example with reference to the following figures, wherein:

[0033] Figures 1a and 1b show exploded views of a known cartridge.

[0034] Figure 2 shows a schematic diagram of the cartridge shown in Figures 1a and 1b.

[0035] Figure 3a shows a schematic diagram of the outer surface of the cartridge cover of the cartridge in Figures 1a and 1b, in which the adhesive label has been removed.

[0036] Figure 3b shows a schematic diagram of the outer surface of the cartridge cover of the cartridge in Figures 1a and 1b.

[0037] Figure 4 shows a bottom view of the cartridge cover of a known cartridge.

[0038] Figure 5 shows a perspective view of an inkjet printhead according to an embodiment of the present invention.

[0039] Figures 6a and 6b show exploded views of the cartridge of the inkjet printhead in Figure 5.

[0040] Figure 7 shows a partial cross-sectional schematic diagram of the microjet device of the inkjet printhead in Figure 5.

[0041] Figure 8 shows a perspective view of a card holder cover according to an embodiment of the present invention.

[0042] Figure 9 shows a bottom view of the cartridge cover according to an embodiment of the present invention.

[0043] Figure 10 shows a perspective view of a soft component according to an embodiment of the present invention.

[0044] Figure 11 shows a bottom view of a soft component according to an embodiment of the present invention.

[0045] Figure 12 shows a perspective view of a cartridge cover according to another embodiment of the present invention.

[0046] Figure 13 shows a bottom view of the cartridge cover according to another embodiment of the present invention.

[0047] Figure 14 shows a schematic diagram of the inner surface of a cartridge cover according to another embodiment of the present invention.

[0048] Figure 15 shows a cross-sectional view of the cartridge cover. [Biomaterial Storage]

[0073] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A cartridge comprising: a cartridge body having an opening and an ink flow orifice, wherein an ink fountain for receiving ink is formed within the cartridge body; a cartridge cover for covering the opening, wherein the cartridge cover is provided with an ink filling hole and a vent hole, and ribs are provided on the inner surface of the cartridge cover; and a flexible member disposed between the cartridge cover and the opening and overlapping the vent hole but not the ink filling hole, wherein when the cartridge cover is installed on the cartridge body and covers the opening, the ribs abut against the flexible member to form a sealing contact between the ribs and the flexible member and to form an expansion space between the cartridge cover and the flexible member, wherein the expansion space has an inlet through which ink can flow from the ink fountain into the expansion space, and the expansion space communicates with the external environment through the vent hole, wherein the expansion space is a tortuous expansion loop.

2. The cartridge as claimed in claim 1, wherein the cartridge includes a porous member and / or a fiber member inserted into the ink fountain, and the size of the flexible member is set to be precisely inserted into the cartridge body, just above the porous member or the fiber member and having an open space corresponding to the ink filling hole.

3. The cartridge as claimed in claim 2, wherein the soft member is provided with two spaced-apart wings at one end of the soft member to form the open space extending to the peripheral edge of the soft member.

4. The cartridge as described in claim 2, wherein the soft component is provided with a through hole aligned with the ink filling hole.

5. The cartridge as described in any one of claims 1 to 4, wherein the soft component is made of rubber.

6. The cartridge as claimed in claim 5, wherein the soft member is a plate-shaped member with a thickness of 1 mm to 2 mm.

7. The cartridge as described in any one of claims 1 to 4, wherein the expansion space contains a porous material.

8. The cartridge as claimed in any one of claims 1 to 4, wherein the expansion space comprises a plurality of expansion chambers fluidly connected via a narrow communication passage, and each expansion chamber is surrounded by ribs connected to the cartridge cover and abutting against the flexible member.

9. The cartridge as claimed in claim 8, wherein the ribs include two curved ribs surrounding the vent.

10. The cartridge as claimed in claim 8, wherein two adjacent ribs are spaced apart from each other to form such narrow communication passages.

11. An inkjet printhead comprising a cartridge as described in any one of claims 1 to 10.

12. The inkjet printhead as claimed in claim 11, wherein the inkjet printhead is a thermal inkjet printhead, the thermal inkjet printhead including a microjet device attached to the cartridge, the microjet device including: a plurality of resistors; a plurality of ejection chambers disposed above the resistors and in fluid communication with the ink flow orifice; and a nozzle plate covering the ejection chambers and provided with nozzles for ejecting ink from the ejection chambers.

13. An inkjet printer comprising an inkjet printhead as described in claim 11 or 12.

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