Reservoir with sealing structure

Abstract

A fluid supply reservoir includes a fluid volume including a. main chamber and a secondary chamber defined by inner walls of the fluid volume, the chambers open to each other, a capillary medium in the main chamber fluidically coupled with the secondary chamber, a sealing structure in the fluid volume, at least partly near the secondary chamber, to support a bottom portion of the capillary medium. The sealing structure is to allow the capillary medium to receive fluid from the main chamber when the capillary medium is not saturated, and to inhibit the fluid flowing from the secondary chamber to the main chamber when the capillary medium is saturated.

Description

Atty. Dkt. No.: 86313309 RESERVOIR WITH SEALING STRUCTURE BACKGROUND

[0001] Some cartridges may include a fluid supply reservoir, which may include a capillary medium and a free fluid chamber. The fluid supply reservoir can store fluid, such as ink or print agents, in the capillary medium and the free fluid chamber. The cartridges may include a fluid ejection system. The fluid in the fluid supply reservoir can be ejected for printing operations through the fluid ejection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Non-limiting examples of the present disclosure are described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. Unless indicated as representing the background art, the figures represent aspects of the disclosure. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0003] FIG. 1 is a block diagram of an example reservoir for providing fluid stored therein.

[0004] FIG. 2A is a schematic diagram of an example reservoir for providing fluid stored therein.

[0005] FIG. 2B is a schematic diagram of an example reservoir for providing fluid stored therein.

[0006] FIG. 2C is a schematic diagram of an example reservoir for providing fluid stored therein.

[0007] FIG. 3A is a schematic diagram of an example reservoir for providing fluid stored therein during a first state.

[0008] FIG. 3B is a schematic diagram of an example reservoir for providing fluid stored therein during a second state.

[0009] FIG. 4 is a block diagram of a portion of an example printing system for performing a printing operation. 1- 4883-5122-0662.1Atty. Dkt. No.: 86313309 DETAILED DESCRIPTION

[0010] Printing systems are used to deposit fluid (e.g., ink) onto a print medium (e.g., paper). Fluid reservoirs (e.g., of printer cartridges) can store and supply the fluid for use in printing by other devices. For example, a printhead of the printing system can deposit the fluid onto the print medium. While the industry has seen overwhelming success in developing manufacturing businesses for cartridges, many challenges still remain.

[0011] While reservoirs constructed with hydrophobic capillary media may have an advantage in controlling fluid stored in the reservoir, the choice of capillary media (e.g., hydrophobic or hydrophilic) can be based on fluid-media compatibility issues. For example, hydrophobic polyurethane (PE) can be used for water-based uid. Fluid with a high solvent level is not compatible with and even can degrade and / or breakdown the PE media due to the limited chemical compatibility of PE, which can adversely affect the delivered fluid. In these cases, a more robust capillary medium, such as a hydrophilic medium, can be used.

[0012] However, with hydrophilic capillary media, there is a need for mechanisms to control the release of the fluid until the capillary media has desaturated to a point where there is space to hold the fluid without fully saturating the media. Prematurely saturating the capillary media can cause the capillary pressure to drop too low to hold the remaining fluid in the reservoir. This is a particular issue for hydrophilic media which freely imbibe fluid up until the capillary media is fully saturated. In addition, when a fluid chamber is empty, the chamber is replaced by air inside the reservoir which can be adjacent to internal fluid ducts and passages. The presence of air directly adjacent to a passage containing fluid can increase the diffusion rate of the air into the passage. In the case of an inkjet pen, this can cause a de-prime of the passages, resulting in the pen non-functional.

[0013] The present disclosure provides techniques for a fluid supply reservoir with capillary media. The reservoir disclosed herein can include a fluid volume including a main chamber and a secondary chamber that are open to each other. The reservoir disclosed herein can include a capillary medium in the main chamber fluidically coupled with the secondary chamber and a sealing structure in the fluid volume. The sealing structure can support a bottom surface of the capillary medium, and can form a fluidic seal. The sealing structure can allow the capillary medium to receive fluid from the main chamber when the capillary medium is not saturated, and inhibit the fluid flowing from the secondary chamber to the main 2- 4883-5122-0662.1Atty. Dkt. No.: 86313309 chamber when the capillary medium is saturated. The sealing structure and the capillary medium can control release of the fluid, such that the release of the fluid can be delayed until the saturation level has dropped to a level where there is room to store the released fluid without loss of capillary pressure and subsequent drooling. In some examples, the sealing structure can open or close a pathway for the fluid and / or air to flow between the main chamber and the secondary chamber based on a saturation level of the capillary medium.

[0014] As describe herein, the reservoir can be designed with hydrophilic media to take advantages of the hydrophilic media while being able to emulate the free-fluid media behavior in hydrophobic media. The techniques disclosed herein can allow for the use of more diverse fluids, thereby opening up a different material compatibility space. In addition, the reservoir with the chamber can have a larger fluid storage capacity compared to a reservoir without one, which can enable more dispensed fluid in the same-sized reservoir. By controlling the release of the fluid, the capillary media can be prevented from prematurely saturating, which provides solutions to the issues described above.

[0015] Furthermore, the techniques disclosed herein enable flexible printing operations such that printing operations (e.g., label) can be performed in a vertical position (or otherwise inclined and / or non-horizontal). Printing operations may be limited by the orientation of the capillary medium and gravity. For example, when a capillary medium is positioned with its long side parallel to the ground, the fluid may be pulled to a top of the capillary medium under the given capillarity. However, when the capillary medium is positioned with its long side perpendicular to the ground, the capillary medium may have a capillarity not high enough to pull the fluid up the full length of the capillary medium. This can cause problems in a pen with a capillary medium that does not use the techniques disclosed herein, for example when the pen is tilted. For example, the fluid can flow through the capillary medium towards the ground. The techniques disclosed herein allow the fluid to stay within the capillary medium, against the pull of gravity, regardless of the orientation of the capillary medium and / or the pen, thereby enabling flexible printing operations.

[0016] FIG. 1 is a block diagram of an example reservoir 100 for providing fluid stored therein. The reservoir 100 includes a fluid volume including a main chamber 104 and a secondary chamber 110. The main chamber 104 can include a capillary medium 120. The reservoir 100 includes a sealing structure 130. Shown in FIG. 1 is a non-limiting example of 3- 4883-5122-0662.1Atty. Dkt. No.: 86313309 the reservoir 100. In some examples, the reservoir 100 can include more, fewer, or different components than shown in FIG. 1.

[0017] The fluid volume of the reservoir 100 can include any volume to contain fluid. In some examples, the fluid volume of the reservoir 100 can be an internal fluid volume defined by a monolithic structure of single molded reservoir walls. The fluid volume can contain the fluid in the main chamber 104, and / or in the capillary medium 120 of the main chamber 104, as discussed below. The fluid volume can contain the fluid in a free space, for example, in the secondary chamber 110, as discussed below.

[0018] The secondary chamber 110 can be a free space to hold a free volume of the fluid. For example, the secondary chamber 110 can hold a free volume of fluid without any capillary medium. In some examples, the secondary chamber 110 can be defined by inner walls of the reservoir 100. For example, the secondary chamber 110 can be a space defined by the inner walls within the fluid volume. In some examples, the secondary chamber 110 can be open to the main chamber 104. For example, the secondary chamber 110 and the main chamber 104 can be fluidically open to each other. In some examples, the secondary chamber 110 can be fluidically coupled with a portion of the capillary medium 120. For example, the secondary chamber 110 can provide the fluid held therein to the capillary medium 120 of the main chamber 104. In some examples, the secondary chamber 110 can be filled with fluid (e.g., ink, printing fluid, etc.). For example, the secondary chamber 110 can be fully filled with the fluid. When the secondary chamber 110 is partially filed with the fluid, the secondary chamber 110 can contain air. In some examples, the secondary chamber 110 can be filled with printing fluid through a filling port.

[0019] The main chamber 104 can be defined by inner walls of the reservoir 100. For example, the main chamber 104 can be a space defined by the inner walls within the fluid volume. In some examples, the main chamber 104 can open to the secondary chamber 110. In some examples, the secondary chamber 110 and the main chamber 104 can be fluidically coupled to each other. For example, the main chamber 104 can receive fluid from the secondary chamber 110. In some examples, the main chamber 104 can include the capillary medium 120 to contain the fluid therein. For example, the capillary medium 120 of the main chamber 104 can hold fluid received from the secondary chamber 110. 4- 4883-5122-0662.1Atty. Dkt. No.: 86313309

[0020] The capillary medium 120 can be or include a material or substance to absorb and transport the fluid through capillary action. For example, the capillary medium 120 can be or include a porous substance, any capillary substance or foam that can generate a negative pressure. In some examples, the capillary medium 120 can be or include a hydrophilic material. For example, the capillary medium 120 can have a hydrophilic property to attract and uptake the fluid or other fluids. In some examples, the capillary medium 120 can be contained within the main chamber 104 of the fluid volume.

[0021] In some examples, the capillary medium 120 can be fluidically coupled with the secondary chamber 110. For example, the capillary medium 120 can receive the fluid from the secondary chamber 110. In some examples, the capillary medium 120 can include a first portion having a first capillarity and a second portion having a second capillarity. In some examples, the second capillarity can be lower than the first capillarity. For example, a bottom portion of the capillary medium 120 can have a first capillarity, and a top portion of the capillary medium can have a second capillarity lower than the first capillarity. In some examples, the capillary medium 120 can be or include multiple capillary media. For example, the capillary medium 120 can include any number of capillary media. Each of the multiple capillary media can have a respective capillarity. In some examples, the capillary medium 120 can have a capillarity gradient from a bottom portion to a top portion of the capillary medium 120. In some examples, a first portion (e.g., the bottom portion) of the capillary medium 120 can be fluidically coupled with the secondary chamber 110. For example, the first portion can be in direct contact with the secondary chamber 110. In some examples, the first portion (e.g., a bottom portion having the first capillarity) can have a volume smaller than a volume of the second portion (e.g., a top portion having the second capillarity).

[0022] The sealing structure 130 can be provided in the reservoir 100. In some examples, the sealing structure 130 can be provided in the fluid volume of the reservoir 100. For example, the sealing structure 130 can be formed near, or at least partly near, the secondary chamber 110 to support a bottom surface of the capillary medium 120. The sealing structure 130 can be located adjacent to and / or between a bottom surface of the main chamber 104 and a top portion of the secondary chamber 110 (or at least one secondary chamber when there are a plurality of the secondary chambers 110).

[0023] In some examples, the sealing structure 130 can be or include a rib (e.g., a longitudinal sealing rib). For example, the sealing structure 130 and / or the longitudinal sealing rib can be 5- 4883-5122-0662.1Atty. Dkt. No.: 86313309 formed as part of a monolithic structure of the reservoir 100. The sealing structure 130 and / or the longitudinal sealing rib can be formed along and / or located adjacent to inner walls of the reservoir 100 (e.g., of the fluid volume). The sealing structure 130 and / or the longitudinal sealing rib can be a structure protruding from the inner walls of the reservoir 100. In some examples, the sealing structure 130 and / or the longitudinal sealing rib can be in contact with a bottom surface of the capillary medium 120. For example, the sealing structure 130 and / or the longitudinal sealing rib can support the capillary medium 120, by contacting at least a portion of the bottom surface of the capillary medium 120. The sealing structure 130 and / or the longitudinal sealing rib can extend along the inner walls of the fluid volume, such that sealing structure 130 and / or the longitudinal sealing rib can contact the capillary medium 120 at the bottom surface of the capillary medium 120 and along a circumference of the capillary medium 120. In some examples, a shape, a size, a location of the sealing structure 130 is not limited, and the sealing structure 130 can be or include any structure to support the capillary medium 120 and / or to form a fluidic seal as described below.

[0024] As described in greater detail below, the sealing structure 130 and the capillary medium 120 can form a fluidic seal to selectively inhibit fluid from flowing between the secondary chamber 110 and the main chamber 104 (e.g., the capillary medium 120). For example, the sealing structure 130 can allow the capillary medium 120 of the main chamber 104 to receive fluid from the secondary chamber 110 when the capillary medium 120 is not saturated. The sealing structure 130 can inhibit the fluid flowing from the secondary chamber 110 to the main chamber 104 when the capillary medium 120 is saturated.

[0025] In some examples, the sealing structure 130 can form the fluidic seal that inhibits the fluid from flowing between the main chamber 104 and the secondary chamber 110 based on a saturation level of the capillary medium 120. For example, the sealing structure 130 can form the fluidic seal that inhibits the fluid from flowing between the secondary chamber 110 and the main chamber 104, when at least a portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 120 (or at least one medium when the capillary medium 120 includes a plurality of capillary media) is saturated (e.g., when the portion of the capillary medium 120 has absorbed the fluid as much as the portion can hold and / or when there is no capacity for further absorption). In some examples, the sealing structure 130 (e.g., the longitudinal rib as discussed above) and the bottom surface of the capillary medium 120 can form the fluidic seal. For example, the longitudinal rib of the 6- 4883-5122-0662.1Atty. Dkt. No.: 86313309 sealing structure 130 and the bottom surface of the capillary medium 120 supported thereby can form the fluidic seal, when the bottom surface of the capillary medium 120 is saturated. The sealing structure 130 can be to not form the fluidic seal between the main chamber 104 and the secondary chamber 110, when the portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 120 is not saturated.

[0026] In some examples, the sealing structure 130 and at least a portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 120 can form a passage that allows fluid to flow between the main chamber 104 and the secondary chamber 110 based on a saturation level of the capillary medium 120. For example, the sealing structure 130 and the first portion can form the passage that allows fluid (e.g., the fluid from the secondary chamber 110) or air to flow between the main chamber 104 and the secondary chamber 110, when at least a portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 120 (or at least one medium when the capillary medium 120 includes a plurality of capillary media) is saturated. The sealing structure 130 and the capillary medium 120 can block the passage, when the portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 120 is saturated.

[0027] In some examples, the sealing structure 130 can form the fluidic seal to control airflow between the secondary chamber 110 and an external environment of the reservoir 100. For example, the sealing structure 130 can allow air from an external environment of the reservoir 100 to flow into the secondary chamber 110 when the capillary medium 120 (e.g., the first portion thereof) is not saturated. The sealing structure 130 and the capillary medium 120 can inhibit the air from the external environment from flowing into the secondary chamber 110 when the capillary medium 120 (e.g., the first portion thereof) is saturated.

[0028] As discussed above, the sealing structure 130 (e.g., the rib) and the capillary medium 120 can form the fluidic seal where the sealing structure 130 (e.g., the rib) and the capillary medium 120 are in contact, thereby forcing air to pass through the capillary medium 120. When the capillary medium 120 is not saturated, the capillary medium 120 can provide a destination for the fluid to flow to, while allowing air to enter the secondary chamber 110 (e.g., through portions not holding the fluid). The air that enters the secondary chamber 110 can occupy the volume left by the fluid absorbed into the capillary medium 120. When the capillary medium 120 is saturated, the air can be inhibited from flowing between the main chamber 104 and the secondary chamber 110 (e.g., inhibited from entering into the secondary 7- 4883-5122-0662.1Atty. Dkt. No.: 86313309 chamber 110), and there is no destination for the fluid to flow to, thereby forming the fluidic seal.

[0029] FIG. 2A, FIG. 2B, and FIG. 2C is a schematic diagram of an example reservoir 200 for providing fluid stored therein. More specifically, FIG.2A shows a perspective view of the reservoir 200, FIG.2B shows a cross-section view of the reservoir 200, and FIG. 3C shows a top view (e.g., when viewed from the +y-axis) of an interior structure of the reservoir 200. The reservoir 200 can be substantially similar to or incorporate features of the reservoir 100. For example, the reservoir 200 includes a secondary chamber 210, a capillary medium 220, and a sealing structure 230, which can be substantially similar to or incorporate features of the secondary chamber 110, the capillary medium 120, and the sealing structure 130, respectively. Shown in FIGS. 2A-2C is a non-limiting example of the reservoir 200. In some examples, the reservoir 200 can include more, fewer, or different components than shown in FIGS.2A-2C. In some examples, as shown, the reservoir 200 can include a lid 240, an output 250, etc. In some examples, the lid 240 can include a protrusion member 242, a passage 244, etc. In some examples, the output 250 can include an ejection filter 255, an ejection path 260, an ejection chamber 265, an ejection circuit 270, etc. In some examples, the capillary medium 220 can include a plurality of media, for example, a first portion 220A (or a first capillary medium), a second portion 220B (or a second capillary medium), etc.

[0030] In some examples, the reservoir 200 includes a fluid volume 201, which can be substantially similar to or incorporate features of the fluid volume described with respect to FIG.1. The fluid volume 201 of the reservoir 200 can include any volume to contain fluid. In some examples, the fluid volume 201 of the reservoir 200 can be defined by a monolithic structure of single molded reservoir walls (e.g., inner walls 202). The fluid volume 201 can contain the fluid in the main chamber 204, and / or in the capillary medium 220 of the main chamber 204, as discussed below. The fluid volume 201 can contain the fluid in a free space, for example, in the secondary chamber 210, as discussed below.

[0031] In some examples, the secondary chamber 210 can be a free space to hold a free volume of the fluid. For example, the secondary chamber 210 can hold a free volume of fluid without any capillary medium. In some examples, the secondary chamber 210 can be defined by the inner walls 202 of the reservoir 200. For example, the secondary chamber 210 can be a space defined by the inner walls 202 within the fluid volume 201. As shown, the secondary chamber 210 can be placed in lower portions of the reservoir 200. In some examples, the 8- 4883-5122-0662.1Atty. Dkt. No.: 86313309 secondary chamber 210 can be open to the main chamber 204. For example, the secondary chamber 210 and the main chamber 204 can be fluidically open to each other. In some examples, the secondary chamber 210 can be fluidically coupled with a portion of the capillary medium 220. For example, the secondary chamber 210 can be directly coupled to a bottom surface of the first portion 220A of the capillary medium 220. The secondary chamber 210 can provide the fluid held therein to the first portion 220A of the capillary medium 220. In some examples, the secondary chamber 210 can be filled with fluid (e.g., ink, printing fluid, etc.). For example, the secondary chamber 210 can be fully filled with the fluid. When the secondary chamber 210 is partially filed with the fluid, the secondary chamber 210 can contain air. In some examples, the secondary chamber 210 can be filled with printing fluid through a filling port. A location of such a filling port is not limited. For example, the filling port can be included in the lid 240. For example, the passage 244 can be used as the filling port. In some examples, as discussed below, the passage 244 can be used to allow the reservoir 200 to communicate air with the local atmosphere.

[0032] The main chamber 204 can be defined by the inner walls 202 of the reservoir 200. For example, the main chamber 204 can be a space defined by the inner walls 202 within the fluid volume 201. In some examples, the main chamber 204 can open to the secondary chamber 210. In some examples, the secondary chamber 210 and the main chamber 204 can be fluidically coupled to each other. For example, the main chamber 204 can receive fluid from the secondary chamber 210. In some examples, the main chamber 204 can include the capillary medium 220 to contain the fluid therein. For example, the capillary medium 220 of the main chamber 204 can hold fluid received from the secondary chamber 210.

[0033] The capillary medium 220 can be placed to absorb and transport the fluid through capillary action. In some examples, the capillary medium 220 can be contained within the main chamber 204 of the fluid volume 201. For example, as shown, the capillary medium 220 can be placed in the main chamber 204 and above the secondary chamber 210, such that the first portion 220A of the capillary medium 220 can receive the fluid from the secondary chamber 210. In some examples, the capillary medium 220 can be sized and shaped to occupy substantially the entire volume of the main chamber 204. For example, the capillary medium 220 can interface with a portion of the lid 240 (e.g., the protrusion member 242) and the inner walls 202 of the reservoir 200. 9- 4883-5122-0662.1Atty. Dkt. No.: 86313309

[0034] In some examples, as shown, the capillary medium 220 can include the first portion 220A having a first capillarity and the second portion 220B having a second capillarity. In some examples, the first portion 220A can be referred to as a downstream capillary medium, and the second portion 220B can be referred to as a upstream capillary medium. In some examples, the first portion 220A and the second portion 220B can be different portions of a single capillary medium, in which each of the first portion 220A and the second portion 220B has a different capillarity. For example, the capillary medium 220 can have a gradient capillarity from a bottom surface of the capillary medium 220 to a top surface of the capillary medium 220. In some examples, as shown, the capillary medium 220 can include a plurality of capillary media, each of which can have a different capillarity. Although shown with the first portion 220A and the second portion 220B, in some examples, the capillary medium 220 can be or include multiple capillary media (e.g., more than two media). For example, the capillary medium 220 can include any number of capillary media. Each of the multiple capillary media can have a respective capillarity. In some examples, the second capillarity of the second portion 220B can be lower than the first capillarity of the first portion 220A. For example, when the capillary medium 220 is formed of porous materials, a size, a density, etc. of pores in each of the first portion 220A and the second portion 220B can be different to achieve the different capillarities. In some examples, when the second portion 220B includes a plurality of portions having different capillarities, the highest capillarity within the second portion 220B can be lower than the capillarity of the first portion 220A. In some examples, the first portion 220A can have a volume smaller than a volume of the second portion 220B. For example, the first portion 220A can be thinner than the second portion 220B. The second portion 220B can be multiple times larger in volume than the first portion 220A. In some examples, the first portion 220A can have a hydrophilic property. In some examples, both the first portion 220A and the second portion 220B can have hydrophilic properties.

[0035] In some examples, as shown in FIG.2B, a bottom surface of the first portion 220A of the capillary medium 220 can be placed above the sealing structure 230, such that the sealing structure 230 can support the bottom surface of the first portion 220A. In some examples, the first portion 230A can conform to the shape of the sealing structure 230 and / or wrap around the sealing structure 230. This contact between the bottom surface of the first portion 220A and the sealing structure 230 can allow for the fluidic seal to be formed between the secondary chamber 210 and the main chamber 204. 10- 4883-5122-0662.1Atty. Dkt. No.: 86313309

[0036] In some examples, the sealing structure 230 can be provided in the reservoir 200 as shown in FIG.2A and FIG. 2B. In some examples, the sealing structure 230 can be provided in the fluid volume 201 of the reservoir 200. For example, the sealing structure 230 can be formed near, or at least partly near, the secondary chamber 210 to support a bottom surface of the capillary medium 220. The sealing structure 230 can be located adjacent to and / or between a bottom portion of the main chamber 204 and a top portion of the secondary chamber 210 (or at least one secondary chamber when there are a plurality of the secondary chambers 210).

[0037] In some examples, the sealing structure 230 can be or include a rib 232 (e.g., a longitudinal sealing rib). In some examples, as shown in FIG. 2C, the rib 232 can be a continuous structure (e.g., a closed shape) formed in an inner portion of the reservoir 200. In some examples, as shown in FIG. 2C, the sealing structure 230 and / or the rib 232 can be formed as part of a monolithic structure of the reservoir 200. The sealing structure 230 and / or the rib 232 can be formed along and / or located adjacent to the inner walls 202 of the reservoir 200 (e.g., of the fluid volume 201). The sealing structure 230 and / or the rib 232 can be a structure protruding from the inner walls 202 of the reservoir 200. The sealing structure 230 and / or the rib 232 can extend along the inner walls 202 of the reservoir 200, such that sealing structure 230 and / or the rib 232 can contact the capillary medium 220 at the bottom surface of the first portion 220A of the capillary medium 220 and along a circumference thereof. In some examples, the rib 232 can be or include an internal seal rib adjacent to the inner walls 202 of the fluid volume 201 that enclose at least the first portion 220A (e.g., the first capillary medium) to seal against a bottom surface of the first portion 220A (e.g., the first capillary medium). In some examples, the rib 232 can be configured to seal the first portion 220A (e.g., the downstream capillary medium) to allow the fluid to flow through the first portion 220A (e.g., the downstream capillary medium) rather than along the inner walls 202 outside the first portion 220A.

[0038] In some examples, the sealing structure 230 and / or the longitudinal sealing rib can support the capillary medium 220, by contacting at least a portion of the bottom surface of the capillary medium 220. In some examples, the rib 232 can have a cross-section thin enough for the bottom surface of the first portion 220A of the capillary medium 220 to warp around, thereby forming the fluidic seal between the main chamber 204 and the secondary chamber 210 (e.g., when the capillary medium 220 is saturated). In some examples, the rib 232 can be 11- 4883-5122-0662.1Atty. Dkt. No.: 86313309 sized, shaped, and / or located such that an area between the rib 232 and the capillary medium 220 (e.g., the bottom surface of the first portion 220A) can be closed (e.g., fluidically sealed off when the capillary medium 220 is saturated).

[0039] Referring to FIG. 2A to FIG. 2C, and as described below, the sealing structure 230 and the capillary medium 220 can form the fluidic seal to selectively inhibit fluid from flowing between the secondary chamber 210 and the main chamber 204 (e.g., the capillary medium 220). For example, the sealing structure 230 can allow the capillary medium 220 of the main chamber 204 to receive fluid from the secondary chamber 210 when the capillary medium 220 is not saturated. The sealing structure 230 can inhibit the fluid flowing from the secondary chamber 210 to the main chamber 204 when the capillary medium 220 is saturated.

[0040] In some examples, the sealing structure 230 can form the fluidic seal that inhibits the fluid from flowing between the main chamber 204 and the secondary chamber 210 based on a saturation level of the capillary medium 220. For example, the sealing structure 230 can form the fluidic seal that inhibits the fluid from flowing between the secondary chamber 210 and the main chamber 204, when at least a portion (e.g., the first portion having a higher capillarity as discussed above) of the capillary medium 220 (or at least one medium when the capillary medium 220 includes a plurality of capillary media) is saturated (e.g., when the portion of the capillary medium 220 has absorbed the fluid as much as the portion can hold and / or when there is no capacity for further absorption). In some examples, the sealing structure 230 (e.g., the rib 232) and the bottom surface of the capillary medium 220 can form the fluidic seal. For example, the rib 232 of the sealing structure 230 and the bottom surface of the capillary medium 220 supported thereby can form the fluidic seal, when the bottom surface of the capillary medium 220 is saturated. The sealing structure 230 can be to not form the fluidic seal between the main chamber 204 and the secondary chamber 210, when the portion (e.g., the first portion 220A having a higher capillarity) of the capillary medium 220 is not saturated.

[0041] In some examples, the sealing structure 230 and at least a portion (e.g., the first portion 220A having a higher capillarity) of the capillary medium 220 can form a passage that allows fluid to flow between the main chamber 204 and the secondary chamber 210 based on a saturation level of the capillary medium 220. For example, the sealing structure 230 and the first portion 220A can form the passage that allows fluid (e.g., the fluid from the secondary chamber 210) or air to flow between the main chamber 204 and the secondary chamber 210, 12- 4883-5122-0662.1Atty. Dkt. No.: 86313309 when at least a portion (e.g., the first portion 220A having a higher capillarity) of the capillary medium 220 (or at least one medium when the capillary medium 220 includes a plurality of capillary media) is saturated. The sealing structure 230 and the capillary medium 220 can block the passage, when the portion (e.g., the first portion 220A having a higher capillarity) of the capillary medium 220 is saturated.

[0042] In some examples, the sealing structure 230 can form the fluidic seal to control airflow between the secondary chamber 210 and an external environment of the reservoir 200. For example, the sealing structure 230 can allow air from an external environment of the reservoir 200 to flow into the secondary chamber 210 when the capillary medium 220 (e.g., the first portion 220A thereof) is not saturated. The sealing structure 230 and the capillary medium 220 can inhibit the air from the external environment from flowing into the secondary chamber 210 when the capillary medium 220 (e.g., the first portion thereof) is saturated.

[0043] In some examples, the first portion 220A of the capillary medium 220 can be compressible in a vertical direction (e.g., towards the sealing structure 230, ±y direction, etc.). For example, the first portion 220A can be compressible and / or flexible such that the first portion 220A and the sealing structure 230 can form the fluidic seal as described above. In some examples, the second portion 220B of the capillary medium 220 can be compressible in a lateral direction (e.g., towards the inner walls 202 of the reservoir 200, ±x and / or ±z directions, etc.). In some examples, the second portion 220B of the capillary medium 220 can be rigid in a vertical direction (e.g., towards the first portion 220A and / or towards the lid 240, ±y direction, etc.). For example, the capillary medium 220 can be rigid to facilitate a fluidic connection between the first portion 220A and the second portion 220B. The second portion 220B can be rigid enough to transfer a force from the protrusion member 242 through the second portion 220B and down to the first portion 220A. This can allow the first portion 220A and the second portion 220B to remain in physical contact, while preventing air from an external environment of the reservoir 200 from flowing into the secondary chamber 210 when the first portion 220A is saturated.

[0044] As discussed above, the sealing structure 230 (e.g., the rib 232) and the capillary medium 220 can form the fluidic seal where the sealing structure 230 (e.g., the rib 232) and the first portion 220A of the capillary medium 220 are in contact, thereby forcing air to pass through the capillary medium 220. When the capillary medium 220 is not saturated, the capillary medium 220 can provide a destination for the fluid to flow to, while allowing air to 13- 4883-5122-0662.1Atty. Dkt. No.: 86313309 enter the secondary chamber 210 (e.g., through portions not holding the fluid). The air that enters the secondary chamber 210 can occupy the volume left by the fluid absorbed into the capillary medium 220. When the capillary medium 220 is saturated, the air can be inhibited from flowing between the main chamber 204 and the secondary chamber 210 (e.g., inhibited from entering into the secondary chamber 210), and there is no destination for the fluid to flow to, thereby forming the fluidic seal.

[0045] This “switchable” sealing can set up a saturation-controlled delay in emptying the secondary chamber 210 into the main chamber 204. The second portion 220B with a lower capillarity empties first, and then the first portion 220A with a higher capillarity empties. Once the first portion 220A desaturates to a point where the secondary chamber 210 is no longer sealed, there is room in the first portion 220A for the fluid in the secondary chamber 210 to be absorbed into the capillary medium 220 without causing drool. In addition, this can enable filling of the secondary chamber 210 during a normal fluid-filling used to fill the capillary medium 220.

[0046] In some examples, the reservoir 200 can include the lid 240. In some examples, the lid 240 can include the protrusion member 242 to apply a force on the capillary medium 220 toward the sealing structure 230. As discussed above, the force can allow the first portion 220A and the second portion 220B to remain in physical contact, while preventing air from an external environment of the reservoir 200 from flowing into the secondary chamber 210 when the first portion 220A is saturated. In some examples, the lid 240 can include the passage 244 to allow air to flow between an interior and an exterior of the reservoir 200.

[0047] In some examples, the reservoir 200 can include the output 250. The output 250 can includes the ejection filter 255, the ejection path 260, and the ejection chamber 265, etc. As shown in FIG. 2B, the output 250 can be connected to the main chamber 204. For example, the output 250 can receive the fluid held in the main chamber 204 (e.g., in the capillary medium 220 of the main chamber 204). In some examples, when the reservoir 200 includes two secondary chambers (e.g., a first secondary chamber 210A and a second secondary chamber 210B as shown in FIG. 2B), the output 250 can be located between the first secondary chamber 210A and the second secondary chamber210B and below the main chamber 204 (e.g., when the reservoir 200 is in an upright position as shown). In some examples, when the first secondary chamber 210A and the second secondary chamber 210B form a single chamber, the secondary chamber 210 can extend along the -y axis in a co-axial 14- 4883-5122-0662.1Atty. Dkt. No.: 86313309 manner while enclosing the output 250. In some examples, at least a portion of the fluid volume 201 extends next to the output 250 under the first portion 220A. The output 250 can supply the fluid received from the main chamber 204 to a printhead (e.g., when connected to the output). In some examples, the fluid held in the capillary medium 220 can be provided to the printhead through the ejection filter 255 and the ejection path 260. In some examples, the reservoir 200 can include the ejection chamber 265. The ejection chamber 265 can distribute the fluid from the capillary medium 220 to the printhead. In some examples, the ejection chamber 265 can include or be connected to the ejection circuit 270. For example, as shown in FIG.2B, the ejection circuit 270 can be disposed downstream of the capillary medium 220 and connected to (or contained within) the output 250 of the reservoir 200. The ejection circuit 270 can be disposed downstream of the output 250.

[0048] In some examples, the sealing structure 230 (and / or the rib 232) and the capillary medium 220 can pass the fluid through the first portion 220A (e.g., the downstream capillary medium) towards the output 250 during printing in any position. For example, the sealing structure 230 (and / or the rib 232) and the capillary medium 220 can pass the fluid through the first portion 220A (e.g., the downstream capillary medium) towards the output 250 during printing in a non-upright position of the cartridge. For example, the sealing structure 230 (and / or the rib 232) and the capillary medium 220 can pass the fluid through the first portion 220A (e.g., the downstream capillary medium) towards the output 250 when printing in a non-horizontal surface. For example, the sealing structure 230 (and / or the rib 232) and the capillary medium 220 can pass the fluid through the first portion 220A (e.g., the downstream capillary medium) towards the output 250 in a direction perpendicular or parallel to a surface on which the reservoir 200 (or the cartridge or the printing device thereof) is installed. That is, the reservoir 200 enables printing on non-horizontal surfaces, such as a vertical or inclined position.

[0049] As such, the reservoir 200 enables flexible printing operations such that printing operations (e.g., label) can be performed in a vertical position (or otherwise inclined and / or non-horizontal). Since the first portion 220A (e.g., the portion having a higher capillarity) has a higher capillary pressure and can draw the fluid in from the second portion 220B (e.g., the portion having a lower capillarity), the first portion 220A can control the flow of fluid and provide the fluid regardless of the orientation of the capillary medium 220 and / or the reservoir 15- 4883-5122-0662.1Atty. Dkt. No.: 86313309 200. The higher capillarity of the first portion 220A allows for the fluid ink to be pulled toward the standpipe that would otherwise be stranded in the printhead.

[0050] FIG. 3A is a schematic diagram of the reservoir 200 for providing fluid stored therein during a first state. FIG. 3B is a schematic diagram of the reservoir 200 for providing fluid stored therein during a second state. More specifically, the first state indicates that the first portion 220A of the capillary medium 220 is saturated (e.g., when the first portion 220A has absorbed the fluid as much as the first portion 220A can hold and / or when there is no capacity for further absorption), and the second state indicates that the first portion 220A of the capillary medium 220 is not saturated.

[0051] As shown in FIG.3A, during the first state, fluid 302 can be pulled through the output 250 from the fluid in the main chamber (e.g., the first portion 220A of the capillary medium 220). To keep the first portion 220A saturated, fluid 304 from the second portion 220B of the capillary medium 220 can be provided to the first portion 220A. This can thereby keep the first portion 220A saturated until the second portion 220B is depleted. Because the first portion 220A is saturated, the fluidic seal (e.g., formed between the main chamber 204 and the secondary chamber 210) can prevent the fluid and / or air from flowing between the main chamber 204 and the secondary chamber 210. Here, the air from an external environment of the reservoir 200 can be inhibited from flowing between the main chamber 204 and the secondary chamber 210 (e.g., inhibited from entering into the secondary chamber 210), and there is no destination in the first portion 220A of the capillary medium 220 for fluid 306 from the secondary chamber 210 to flow to, thereby forming the fluidic seal.

[0052] As shown in FIG. 3B, during the second state, fluid 352 can be pulled through the output 250 from the fluid in the main chamber 204 (e.g., the first portion 220A of the capillary medium 220). Since the second portion 220B has been already depleted (and / or completely desaturated), no fluid is provided from the second portion 220B to the first portion 220A, thereby desaturating the first portion 220A. When the first portion 220A is sufficiently desaturated, fluid 356 from the secondary chamber 210 can be absorbed into the first portion 220A to occupy the desaturated zones through capillary action. That is, when the capillary medium 220 is not saturated, the capillary medium 220 can provide a destination for the fluid 356 to flow to, while allowing air 354 to enter the secondary chamber 210 (e.g., through portions not holding the fluid and / or adjacent to an area where the sealing structure 230 and the first portion 220A are in contact). The air 354 that enters the secondary chamber 210 can 16- 4883-5122-0662.1Atty. Dkt. No.: 86313309 occupy the volume left by the fluid 356 absorbed into the capillary medium 220. In some examples, the air 354 from an external environment of the reservoir 200 can flow through the first portion 220A, pass around the sealing structure 230, and flow into the secondary chamber 210 to backfill the volume in the secondary chamber 210 left by the fluid 356.

[0053] The fluid that is absorbed into the capillary medium 220 (e.g., the fluid 356) does not stay where it was introduced. Rather than forming a highly saturated region where it was introduced (e.g., a bottom portion of the first portion 220A of the capillary medium 220), the fluid 356 can spread out in the capillary medium 220 (e.g., the first portion 220A) until a uniform level of saturation is established. This makes it nearly impossible to form a fully saturated region adjacent to the secondary chamber 210 and thus to stop fluid from flowing between the first portion 220A and the secondary chamber 210. This capillary action and the use of multiple portions (e.g., the first portion 220A, the second portion 220B) of the capillary medium 220 can allow for controlled release of the fluid. When the reservoir 200 is filled with fluid, the first portion 220A (e.g., with the higher capillarity) can fully saturate before the second portion 220B (e.g., with the lower capillarity) begins to be filled. In this manner, the first portion 220A can block fluid from leaving the secondary chamber 210 and air (e.g., from an external environment) from reaching the secondary chamber 210, while the second portion 220B can be filled and / or saturated to achieve a certain capillary pressure. In addition, the second portion 220B can desaturate first, before the first portion 220A begins to desaturate. This can delay the release of the fluid until late in the desaturation cycle of the first portion 220A, while allowing for a reservoir saturation level at which the fluid is released to be tuned by adjusting the relative volume (and / or a density, a capillarity, a pore size, etc.) of the first portion 220A and the second portion 220B.

[0054] FIG. 4 is a block diagram of a portion of an example printing system 400 for performing a printing operation. The printing system 400 can include a cartridge 410 and a printhead 420, among other components (not shown). In some examples, the cartridge 410 can be or include a fluid cartridge (e.g., an inkjet cartridge) or a pen. The cartridge 410 can supply fluid 415 to the printhead 420. The printhead 420 can provide fluid 425 to perform a printing operation.

[0055] As shown in FIG. 4, the cartridge 410 can include the reservoir 100 (or the reservoir 200) described above. In some examples, the cartridge 410 can include a fluid ejection circuit (e.g., the ejection circuit 270) downstream of a capillary medium in the reservoir 100, and 17- 4883-5122-0662.1Atty. Dkt. No.: 86313309 can eject the fluid through the printhead 420. For example, as described with respect to FIGS. 2A-2C, the cartridge 410 can supply the fluid through an output (e.g., the output 250) to the printhead 420.

[0056] As describe herein, the reservoir can be designed with hydrophilic media to take advantages of the hydrophilic media while being able to emulate the free-fluid media behavior in hydrophobic media. The techniques disclosed herein can allow for the use of more diverse fluids, thereby opening up a different material compatibility space. In addition, the reservoir with the free fluid chamber can have a larger fluid storage capacity compared to a reservoir without one, which can enable more dispensed fluid in the same-sized reservoir. By controlling the release of the fluid, the capillary media can be prevented from prematurely saturating.

[0057] In one aspect of the present disclosure, a fluid supply reservoir is disclosed. The fluid supply reservoir includes a fluid volume including a main chamber and a secondary chamber defined by inner walls of the fluid volume, the chambers open to each other, a capillary medium in the main chamber fluidically coupled with the secondary chamber, a sealing structure in the fluid volume, at least partly near the secondary chamber, to support a bottom surface of the capillary medium, wherein the sealing structure is to allow the capillary medium to receive fluid from the main chamber when the capillary medium is not saturated, and inhibit the fluid flowing from the secondary chamber to the main chamber when the capillary medium is saturated.

[0058] In yet another aspect of the present disclosure, a fluid ejection cartridge is disclosed. The fluid ejection cartridge includes the fluid supply reservoir as discussed herein and includes a fluid ejection circuit downstream of the capillary medium, connected to a fluid output of the fluid supply reservoir, in upright reservoir position located below the main chamber and between a first portion and a second portion of the secondary chamber.

[0059] In yet another aspect of the present disclosure, a fluid supply reservoir is disclosed. The fluid supply reservoir includes a fluid volume to hold fluid, the fluid volume including a main chamber and secondary chambers, the fluid volume defined by a monolithic structure of single molded reservoir walls, a longitudinal sealing rib as part of the monolithic structure, the longitudinal sealing rib formed along and protruding from inner walls of the fluid supply reservoir, and located adjacent to and between a bottom portion of the main chamber and a 18- 4883-5122-0662.1Atty. Dkt. No.: 86313309 top portion of at least one secondary chamber, and an output connected to the main chamber between the secondary chambers, the output to supply fluid to a printhead when connected to the output.

[0060] In yet another aspect of the present disclosure, a fluid supply reservoir is disclosed. The fluid supply reservoir includes a fluid volume including a main chamber and a secondary chamber defined by inner walls of the fluid volume, the chambers open to each other, at least one capillary medium in the main chamber fluidically coupled with the secondary chamber, the at least one capillary medium including a first portion having a first capillarity and a second portion having a second capillarity lower than the first capillarity, and a sealing structure in the fluid volume, at least partly near the secondary chamber, to form a fluidic seal that inhibits fluid from flowing between the main chamber and the secondary chamber when the at least one capillary medium is saturated.

[0061] It should be understood that examples described herein should be considered in a descriptive sense and not for purposes of limitation. Descriptions of features or aspects within each example should be considered as available for other similar features or aspects in other examples. While examples have been described with reference to the figures, it should be understood that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

[0062] The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the description. Therefore, the foregoing examples provided in the figures and described herein should not be construed as limiting of the scope of the disclosure, which is defined in the Claims.

[0063] The disclosure has been described above with reference to the various examples. However, it is to be understood by those of ordinary skill in the art that various modifications may be made in form and detail without departing from the scope of the disclosure as defined by the appended claims and their equivalents.

[0064] Conditional language used herein, such as, among others, "can," "may," “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain examples include, while other examples do 19- 4883-5122-0662.1Atty. Dkt. No.: 86313309 not include, certain features, elements, etc. Thus, such conditional language is not generally intended to imply that an example includes logic for deciding, with or without other input or prompting, whether these features, elements, etc. are included or are to be performed in any particular example. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0065] While the above detailed description has shown, described, and pointed out novel features as applied to various examples, it can be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated can be made without departing from the spirit of the disclosure. As can be recognized, certain examples described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others.

[0066] The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components.

[0067] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity.

[0068] It should be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "includes" should be interpreted as "includes but is not limited to," etc.). It should be further understood by those within the art that if a specific number of an introduced claim 20- 4883-5122-0662.1Atty. Dkt. No.: 86313309 recitation is intended, such an intent should be explicitly recited in the claim, and in the absence of such recitation no such intent is present. Furthermore, in those instances where a convention analogous to "one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances, where a convention analogous to " one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It should be understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B" or "A and B." Furthermore, unless otherwise noted, the use of the words “approximate,” “about,” “around,” “substantially,” etc., mean plus or minus ten percent. 21- 4883-5122-0662.1

Claims

Atty. Dkt. No.: 86313309 WHAT IS CLAIMED IS:

1. A fluid supply reservoir comprising: a fluid volume comprising a main chamber and a secondary chamber defined by inner walls of the fluid volume, the chambers open to each other; a capillary medium in the main chamber fluidically coupled with the secondary chamber; a sealing structure in the fluid volume, at least partly near the secondary chamber, to support a bottom surface of the capillary medium; wherein the sealing structure is to: allow the capillary medium to receive fluid from the main chamber when the capillary medium is not saturated; and inhibit the fluid flowing from the secondary chamber to the main chamber when the capillary medium is saturated.

2. The fluid supply reservoir of claim 1, wherein the sealing structure comprises a rib in contact with the bottom surface of the capillary medium, the rib located adjacent to the inner walls of the fluid volume.

3. The fluid supply reservoir of claim 2, wherein the rib extends along the inner walls of the fluid volume to contact the capillary medium at the bottom surface of the capillary medium and along a circumference of the capillary medium.

4. The fluid supply reservoir of any preceding claim, wherein: the sealing structure and the capillary medium form a passage that allows the fluid to flow between the main chamber and the secondary chamber when the capillary medium is not saturated, and the sealing structure and the capillary medium block the passage when the capillary medium is saturated. 22- 4883-5122-0662.1Atty. Dkt. No.: 86313309 5. The fluid supply reservoir of any preceding claim, wherein the capillary medium comprises a first portion having a first capillarity and a second portion having a second capillarity lower than the first capillarity.

6. The fluid supply reservoir of claim 5, wherein the first portion is fluidically coupled with the secondary chamber and has a volume smaller than a volume of the second portion; and wherein the secondary chamber is to hold a free volume of fluid without the capillary medium.

7. A fluid ejection cartridge, comprising the fluid supply reservoir of any preceding claim, and comprising a fluid ejection circuit downstream of the capillary medium, connected to a fluid output of the fluid supply reservoir, in upright reservoir position located below the main chamber and between a first portion and a second portion of the secondary chamber.

8. A fluid supply reservoir comprising: a fluid volume to hold fluid, the fluid volume including a main chamber and secondary chambers, the fluid volume defined by a monolithic structure of single molded reservoir walls; a longitudinal sealing rib as part of the monolithic structure, the longitudinal sealing rib formed along and protruding from inner walls of the fluid supply reservoir, and located adjacent to and between a bottom portion of the main chamber and a top portion of at least one secondary chamber; and an output connected to the main chamber between the secondary chambers, the output to supply fluid to a printhead when connected to the output.

9. The fluid supply reservoir of claim 8, wherein the longitudinal sealing rib is to inhibit the fluid from flowing between the secondary chambers and the main chamber based on a saturation level of a capillary medium in the main chamber. 23- 4883-5122-0662.1Atty. Dkt. No.: 86313309 10. The fluid supply reservoir of any preceding claim, comprising the capillary medium in the main chamber that comprises a first portion having a first capillarity and a second portion having a second capillarity lower than the first capillarity.

11. The fluid supply reservoir of any preceding claim, wherein the capillary medium has a hydrophilic property.

12. A fluid supply reservoir comprising: a fluid volume comprising a main chamber and a secondary chamber defined by inner walls of the fluid volume, the chambers open to each other; at least one capillary medium in the main chamber fluidically coupled with the secondary chamber, the at least one capillary medium comprising a first portion having a first capillarity and a second portion having a second capillarity lower than the first capillarity; and a sealing structure in the fluid volume, at least partly near the secondary chamber, to form a fluidic seal that inhibits fluid from flowing between the main chamber and the secondary chamber when the at least one capillary medium is saturated.

13. The fluid supply reservoir of claim 12, wherein the sealing structure is to allow air from an external environment of the fluid supply reservoir to flow into the secondary chamber when the at least one capillary medium is not saturated.

14. The fluid supply reservoir of any preceding claim, wherein the sealing structure comprises a rib in contact with a bottom surface of the at least one capillary medium; and wherein the rib and the bottom surface of the at least one capillary medium form the fluidic seal when the at least one capillary medium is saturated.

15. The fluid supply reservoir of any preceding claim, comprising a lid of the fluid supply reservoir, the lid comprising a protrusion member to apply a force on the at least one capillary medium toward the sealing structure. 24- 4883-5122-0662.1Atty. Dkt. No.: 86313309 16. A fluid supply for a cartridge, comprising: an internal fluid volume; a fluid output to eject fluid; a downstream and upstream capillary medium, the downstream capillary medium having a higher capillarity than the upstream capillary medium, the downstream capillary medium extending between the fluid output and the upstream capillary medium, wherein at least the downstream capillary medium has a hydrophilic property.

17. The fluid supply cartridge of claim 16, wherein both the downstream and the upstream capillary media have hydrophilic properties.

18. The fluid supply cartridge of any preceding claim, comprising an internal seal rib adjacent to inner walls of the internal fluid volume that enclose at least the downstream capillary medium, to seal against a bottom region of the downstream capillary medium.

19. The fluid supply cartridge of any preceding claim, wherein, in an upright position of the cartridge, the fluid output extends below the downstream capillary medium, the fluid output is to connect to a fluid ejection circuit, at least a portion of the internal fluid volume extends next to the fluid output under the downstream capillary medium, and a rib seals the downstream capillary medium to allow the fluid to flow through the downstream capillary medium rather than along inner walls outside of the capillary medium.

20. The fluid supply cartridge of any preceding claim, wherein the rib and the downstream capillary media are to pass the fluid through the downstream capillary medium towards the fluid output during printing in a non-upright position of the cartridge, for example when printing against a non-horizontal surface.

21. The fluid supply cartridge of any preceding claim, comprising a fluid ejection circuit downstream of the fluid output. 25- 4883-5122-0662.1Atty. Dkt. No.: 86313309 22. The fluid supply cartridge of any preceding claim, wherein the fluid is provided from the downstream capillary medium to the fluid output in a direction parallel to a surface on which the cartridge is installed.

23. The fluid supply cartridge of any preceding claim, wherein the fluid is provided from the downstream capillary medium to the fluid output in a direction perpendicular to a surface on which the cartridge is installed. 26- 4883-5122-0662.1

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