Inkjet cartridges

Abstract

To provide an inkjet cartridge comprising a pressure regulator composed of a non-metallic material.SOLUTION: An inkjet cartridge 100 is provided, comprising a reservoir operable of operating to contain a solution, and a pressure regulator 130 disposed in the reservoir, the pressure regulator comprising a non-metallic material. Alteration or material change of the solution can be suppressed.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present disclosure relates to inkjet cartridges. [Background technology]

[0002] An inkjet cartridge is typically a component of an inkjet printer that contains a solution for printing onto a substrate by spraying droplets of the solution onto the substrate in response to commands from the inkjet printer. The solution may be, for example, ink for printing onto a substrate such as paper, or a reagent for jetting or printing onto a substrate for various analytical or scientific applications. An inkjet cartridge contains one or more reservoirs of solution connected to a printhead. Examples of inkjet cartridges include thermal inkjet cartridges and piezoelectric inkjet cartridges. Thermal inkjet cartridges typically include a printhead containing an array of nozzles, a reservoir of solution (e.g., ink, reagent) behind the nozzles, and a heating element comprising a metal plate or resistor adjacent to the reservoir. In response to a signal from the inkjet printer, a current pulse flows through the heating element, vaporizing a small amount of solution in the reservoir and generating enough pressure to expel a drop of solution from a nozzle in the printhead. Piezoelectric inkjet cartridges typically use piezoelectric crystals in the nozzles rather than heating elements. When an electric current is applied, the crystals change shape and size, increasing pressure within the inkjet cartridge's solution channel and forcing a droplet of solution out the nozzle. One parameter in both thermal and piezoelectric inkjet cartridges is the backpressure, or reservoir pressure. Backpressure, or reservoir pressure, is below atmospheric pressure (negative pressure). [Brief explanation of the drawings]

[0003] [Figure 1A] FIG. 2 is a perspective view of the inkjet cartridge. [Figure 1B]FIG. 1B is an exploded perspective view of the inkjet cartridge of FIG. 1A. [Figure 2] 2 is a cross-sectional view of the inkjet cartridge of FIG. 1A taken along line 2-2'. [Figure 3] 3 is a cross-sectional view of the inkjet cartridge of FIG. 1A taken along line 3-3' of FIG. 2. [Figure 4] 1B is a schematic side view of the pressure regulator of the inkjet cartridge of FIG. 1A in a relaxed state. [Figure 5] 3 is a cross-sectional side view of the inkjet cartridge of FIG. 1A through line 3-3' of FIG. 2 with a solution (eg, ink, reagent) occupying a substantial volume within the reservoir (eg, the reservoir is full). [Figure 6] 3 is a cross-sectional side view of the inkjet cartridge of FIG. 1A through line 3-3' of FIG. 2 with a solution (e.g., ink, reagent) occupying a small volume in the reservoir (e.g., the reservoir is empty or nearly empty). [Figure 7] 1 is a graph of the force exerted by a metal bow or leaf spring including two diamond-shaped strips on opposing walls of an inkjet cartridge for different spring heights or gaps. [Figure 8] 1 is a graph of the force exerted on opposing walls of an inkjet cartridge by different bow or leaf springs comprising two diamond-shaped strips of polyethylene terephthalate (PET) corresponding to different spring heights or gaps. [Figure 9] 1 is a graph of back pressure or negative pressure versus reservoir volume for an inkjet cartridge pressure regulator using a bow spring or a leaf spring, and three pressure regulators containing two diamond-shaped strips made of either metal or polyethylene terephthalate (PET). [Figure 10A] 10 is a graph of the force exerted on opposing walls of an inkjet cartridge by five pressure regulators similar to pressure regulator 130, which use bow or leaf springs including two diamond-shaped strips of polycarbonate (PC) or polypropylene (PP) of different thicknesses and opposing plates of similar material. [Figure 10B]10 is a graph of the force exerted on opposing walls of an inkjet cartridge by six pressure regulators similar to pressure regulator 130, using bow or leaf springs comprising two diamond-shaped strips of polypropylene (PP) or polyvinyl chloride (PVC) of different thicknesses and opposing plates of similar material. [Figure 11A] 1 shows a graph of back pressure or negative pressure for five inkjet cartridges using a pressure regulator similar to pressure regulator 130, which uses a bow or leaf spring including two diamond-shaped strips of PC or PP and opposing plates of similar material. [Figure 11B] 1 shows a graph of the back pressure or negative pressure of six inkjet cartridges using a pressure regulator similar to pressure regulator 130, which uses a bow or leaf spring that includes two diamond-shaped strips of PP or PVC and opposing plates of similar material. DETAILED DESCRIPTION OF THE INVENTION

[0004] An inkjet cartridge is disclosed that is suitable for containing a solution (e.g., ink, reagent) and for being installed in an inkjet printer and for ejecting the solution as directed by a signal from the inkjet printer. The inkjet cartridge uses non-metallic materials, such as polymers (e.g., plastics), for all components that may come into contact with the solution (e.g., ink, reagent) between the reservoir and the printhead. The non-metallic materials may be selected to be inert to the solution (e.g., ink, reagent) in the inkjet cartridge reservoir so as not to alter or physically change the solution or degrade the inkjet cartridge components. The inkjet cartridge includes a casing defining an interior volume; a printhead coupled to a snout portion of the casing; a first wall and an opposing second wall, each constructed from a flexible, non-resilient, and non-metallic material, defining a reservoir within the interior volume; and a pressure regulator disposed within the reservoir and including a spring and a first plate and a second plate, each constructed from a non-metallic material, wherein the spring is coupled to a first side of the first plate and a first side of the second plate so as to be disposed between the first plate and the second plate, the second side of the first plate being coupled to the first wall, and the second side of the second plate being coupled to the second wall.

[0005] FIGS. 1A-3 show different views of an example inkjet cartridge. A thermal inkjet cartridge is described. It is understood that the use of non-metallic materials as described may also be incorporated into piezoelectric inkjet cartridges. Inkjet cartridge 100 includes a body defining the exterior of the cartridge. In this example, as seen in FIGS. 1A and 1B, the body includes a casing 110 having a generally rectangular perimeter (length L and width W) with a downwardly projecting snout 1105 on one side of the bottom, as shown. Typical dimensions of casing 110 include, but are not limited to, a length L of 2 cm to 8 cm, a depth D of 2 cm to 8 cm, and a width W of 1 cm to 3 cm. Casing 110 may take on any number of other shapes and dimensions, such as shapes and dimensions to accommodate a desired solution volume and / or enclosure of a printer / plotter housing when inkjet cartridge 100 is enclosed within such housing. The width W of the casing 110 defines the interior volume of the inkjet cartridge 100 and separates opposing housing sidewalls 112 and 114. The housing sidewalls 112 and 114 have a shape similar to that of the casing 110 and are affixed to the casing 110 by adhesive, thermal bonding, or a press fit. The sidewalls 112 and 114 may be made of a rigid polymer or plastic material similar to that of the casing 110, or may be made of a material that is more flexible in the presence of atmospheric pressure. In another example, the sidewalls 112 and 114 may not be present (i.e., the sidewalls are optional). The snout portion 1105 of the inkjet cartridge 100 may be part of the casing 110 and provides a path for evacuation of the ink solution within the inkjet cartridge 100. The snout portion 1105 has an evacuation opening 1105 in its bottom wall and has an inkjet printhead 170 (see FIG. 2) affixed to its exterior surface. The casing 110, including the snout portion 1105, may be made of a rigid polymer or plastic material, typically by molding techniques. The side walls 112 and 114, if present, may be made of a rigid polymer or plastic material, typically by molding techniques.

[0006] A frame 120 is disposed within the body defined by the casing 110 and side walls 112 and 114. The frame 120 has a shape similar to that of the casing 110 and is formed with an outer periphery smaller than the inner periphery of the casing 110 so that the frame 120 fits snugly against each of the inner walls of the casing 110. The frame 120 is made of a relatively rigid, non-metallic material, such as a relatively rigid polymer or plastic. Examples of polymers or plastics suitable for the frame 120 include, but are not limited to, polyoxymethylene (POM), high-density polyethylene (HDPE), polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and nylon. The frame 120 has a thickness suitable to provide a surface area for mounting walls to define reservoirs within the body of the cartridge 100. A typical thickness t is on the order of 0.5 to 5 millimeters (mm).

[0007] Walls 122 and 124 are connected to opposing sides 121a and 121b of frame 120, respectively. Walls 122 and 124 may be connected to sides 121a and 121b of frame 120, respectively, to form a continuous seal between the walls and frame 120 by adhesive or heat welding. Walls 122 and 124, together with the inner periphery of frame 120, define a reservoir for storing a solution, such as ink or reagent, to be ejected from inkjet cartridge 100. Walls 122 and 124 are each made of a non-metallic material, such as a polymer or plastic, that is chemically inert to the solution (ink, reagent, etc.) that may be contained between the walls. The material of walls 122 and 124 may be a flexible material that is inelastic or resistant to spontaneously returning to its original shape after contraction or distortion. Such a material allows walls 122 and 124 to collapse inward as the volume of solution in the reservoir decreases. Suitable materials include, but are not limited to, polyethylene (various densities), polyethylene terephthalate (PET), polyester, or nylon with thicknesses on the order of 1 mil to 3 mils. Another example of a suitable material for walls 122 and 124 is a foil (e.g., aluminum foil) coated with a chemically inert polymer on at least one side that will come into contact with the solution contained between the walls. Walls 122 and 124 may be connected to frame 120 at their peripheries by adhesive or heat welding. An opening 160 is formed in the bottom of frame 120 to provide a passageway for introducing solution (e.g., ink, reagent) into the reservoir. Opening 160 may be closed or plugged with a stopper 165 made of a polymer or plastic material, such as PET, nylon, polyester, or HDPE. As an alternative to the reservoir assembly of frame 120, walls 122 and 124 defining the reservoir, the reservoir assembly may be a pouch or bag sized to fit within casing 110 and side walls 112 and 114 and having properties to contain the solution introduced therein. Such a pouch or bag may be made of a flexible material that is inelastic or resistant to spontaneous return to its original shape after being shrunk or distorted, and is chemically inert to the solution that will be contained in the reservoir.Exemplary materials include, but are not limited to, polyethylene (various densities) having thicknesses on the order of 0.25 mils to 3 mils, PET, polyester, nylon, or foil (e.g., aluminum foil) coated with a chemically inert polymer on at least one side that will come into contact with the solution contained between the walls.

[0008] 1A-3, a pressure regulator 130 is disposed within a reservoir defined by wall 122, wall 124, and a portion of frame 120. Pressure regulator 130 includes a spring 1305, a first plate 1304, and a second plate 1306, each made of a non-metallic material, such as a polymer or plastic, that is inert to the solution contained within the reservoir. Exemplary non-metallic materials include polymeric materials having a glass transition temperature between -120°C and 180°C, such as, but not limited to, between 0°C and 180°C, or between 30°C and 180°C. Representative materials for the components of the pressure regulator 130 (spring 1305, first plate 1304, and second plate 1306) include, but are not limited to, high-density polyethylene (HDPE), polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), nylon, polyether ether ketone (PEEK), polyphenylene sulfide (PPS), or polyvinyl chloride (PVC). The material of the spring 1305 may be the same as or different from the material of the first plate 1304 and / or second plate 1306. The pressure regulator 130 may be centrally disposed within the reservoir. The spring 1305 is disposed between the first plate 1304 and the second plate 1306 and is configured or designed to transmit a force F generated by the spring 1305 to each of the first plate 1304 and the second plate 1306, urging the plates apart. The spring 1305 is typically a bow spring or leaf spring, and includes two diamond-shaped strips of non-metallic material formed with an arc at or near its center and connected to each other at opposite ends of the same diagonal (e.g., by opposing hook connections) to form a generally oval spherical shape. The diamond shape may be defined by a first diagonal D1 and a second diagonal D2 (see FIG. 2). A typical length of the first diagonal D1 is 1 cm to 4 cm, e.g., 2 cm to 3 cm, and a typical length of the second diagonal D2 is 4 cm to 7 cm, e.g., 5 cm to 6 cm. The first plate 1304 and the second plate 1306 are rectangular in shape and generally parallel to each other.The first plate 1304 and the second plate 1306 typically have a length l of 4 cm to 7 cm, e.g., 5 cm to 6.5 cm, and e.g., 5 cm to 6 cm, and a width w of 2 cm to 5 cm, e.g., 3 cm to 4.5 cm, and e.g., 3 cm to 4 cm. The first plate 1304 and the second plate 1306 typically have a thickness of 0.2 millimeters (mm) to 0.6 mm, e.g., 0.3 mm to 0.5 mm, and e.g., 0.35 mm to 0.45 mm. The spring 1305, which may be a bow spring or a leaf spring as described above, may be connected to the center of each of the first plate 1304 and the second plate 1306, e.g., by adhesive or hot glue. The opposite ends of the first plate 1304 and the second plate 1306 may be connected to the wall 122 and the wall 124, respectively, e.g., by hot glue or hot glue.

[0009] With respect to pressure regulator 130, spring 1305, plate 1304, and plate 1306 are each made of a non-metallic material, such as a polymer or plastic. Pressure regulator 130 must be capable of generating a backpressure or negative pressure within the reservoir by transmitting the force generated by spring 1305 outward to plates 1304 and 1306, respectively, and transmitting that force to walls 122 and 124, respectively. The selected backpressure or negative pressure is, in one example, between 1 inch of water column (approximately 250 Pascals) and 12 inches of water column (approximately 3000 Pascals), and in another example, between 1 inch of water column (approximately 250 Pascals) and 6 inches of water column (approximately 1500 Pascals). In the example cartridge described herein, a backpressure or negative pressure less than 1 inch of water column risks leaking of solution (ink, reagent, etc.) from the nozzles, while a backpressure or negative pressure greater than 12 inches of water column results in poor jetting (printing) quality. The value or range of such backpressure may vary depending on other factors in the cartridge design, such as the cartridge design, reservoir tank size, ink reservoir wall flexibility, nozzle diameter, and the size and power of the resistor plate or piezo crystal mechanism. For metal springs, springs with low spring constants and relatively high breakaway forces have been found to achieve the desired backpressure or negative pressure. A bow or leaf spring includes two diamond-shaped strips formed by an arc at or near the center and connected to each other at opposite ends of the same diagonal, resulting in an overall ellipsoidal shape, resulting in a relatively constant force generated by the spring as a function of the spring curvature. The non-metallic (e.g., plastic, polymer) pressure regulator 130 described herein mimics the spring characteristics of a metal spring.

[0010] As described above, the frame 120 has a shape similar to that of the casing 110. The shape includes a snout 1205 configured to be disposed within the snout 1105 when the frame 120 is disposed within the casing 110. The snout 1205 provides a path for the solution in the reservoir of the inkjet cartridge 100 to drain and includes a drain opening in its bottom wall aligned with the drain opening in the snout 1105. At least one filter is disposed within the snout 1205. FIG. 1 shows two filters 140 disposed on opposite sides of the snout 1205. Each filter 140 may have any desired shape (e.g., rectangular, circular), and the filters may be disposed within a frame (e.g., a rectangular frame for a rectangular filter), where the filters are configured to be attached to the frame 120 by adhesive, force, snap fit, thermal bonding, or the like. Each filter 140 is disposed in fluid communication with the solution in the reservoir. This may be accomplished by placing the filter 140 within the frame 120 and then attaching the walls 122 and 124 to the snout 1205 to surround the filter (e.g., the walls 122 and 124 each have a shape similar to the profile of the frame 120 with the snout 1205). The material for the filter is chemically inert to the solution intended for the reservoir. Examples include non-metallic filter materials such as nylon and polyester. If the filter has a frame, the material of the frame is also chemically inert to the solution intended for the reservoir. Suitable materials include, but are not limited to, POM, HDPE, PP, ABS, PVC, nylon, PEEK, PPS, or copolymers.

[0011] The pressure regulator 130 and filter 140 may be placed within the frame 120, and the wall 122 may be attached to the first plate 1304 and the wall 124 may be attached to the second plate 1306 to form a reservoir assembly. The reservoir assembly may then be attached to the casing 110. The walls 112 and 114 may then be affixed to opposite sides of the casing 110. The reservoir of the ink cartridge 100 may then be filled with a solution (e.g., ink, reagent) by introducing the solution through the opening 160 in the frame 120. Once introduced, the opening 160 may be closed or blocked with a stopper 165. The inkjet cartridge 100 as described may be a disposable cartridge (i.e., the contents of the cartridge are used and then discarded) or a refillable cartridge.

[0012] A pressure regulator 130 in the reservoir of inkjet cartridge 100 provides a spring force to the reservoir that changes pressure in response to changes in the solution (e.g., ink, reagent) in the reservoir (changes in the volume of solution present in the reservoir). The spring force provided by pressure regulator 130 maintains a subatmospheric or negative pressure to inhibit leakage of the solution (e.g., ink, reagent) from inkjet cartridge 100. As solution (e.g., ink, reagent) is withdrawn from the reservoir, atmospheric pressure will cause flexible reservoir walls 122 and 124 and plates 1304 and 1306 of pressure regulator 130 to move toward each other until spring 1305 assumes a flat or essentially flat configuration in which plates 1304 and 1306 are in close contact with each other, such that the reservoir is substantially empty of solution.

[0013] Figures 4-6 show schematic diagrams of pressure regulator operation. Figure 4 shows pressure regulator 130 in a relaxed state, e.g., outside a reservoir. In this example, spring 1305 has a typical spring height of 30 mm to 45 mm, e.g., 30 mm to 40 mm or 30 mm to 35 mm, measured as the distance between plates 1304 and 1306. Figures 5-6 show pressure regulator 130 in an inkjet cartridge reservoir and the changing configuration of spring 1305 and walls 1304, 1306 depending on the volume of solution in the reservoir. In Figure 5, there is a significant amount of solution (ink, reagent, etc.) in the reservoir (e.g., a full reservoir). Atmospheric pressure (air) outside walls 122 and 124 (the sides facing the reservoirs) resists the outward force of the solution in the reservoirs and the spring force applied by spring 1305 to walls 1304 and 1306, so in this example, spring 1305 has a spring height of, for example, 16 mm. In Figure 6, the volume of solution (e.g., ink, reagent) in the reservoirs is very low or empty. Atmospheric pressure (air) outside walls 122 and 124 resists the outward pressure of spring 1305 until the spring height of spring 1305 is near zero, to the point where walls 122 and 124 of pressure regulator 130 are nearly in contact.

[0014] As mentioned above, with the exception of the printhead, all components of the ink cartridge 100 that may come into contact with the solution (e.g., ink, reagents) therein are made of or coated with non-metallic materials. Such components include the reservoir assembly (frame 120, walls 112, 114), pressure regulator 130, filter 140, and stopper 165. In this manner, the ink cartridge 100 provides a metal-free path for the solution from the reservoir to the printhead. In addition to being non-metallic, the material of each of these components intended to come into contact with the solution in the reservoir may be selected to be chemically inert to the solution, so that reaction or degradation of the solution or component does not occur due to contact. The materials of the reservoir assembly (frame 120, walls 112, 114), pressure regulator 130, filter 140, and stopper 165 may be the same or different.

[0015] Table 1 shows the results of the force exerted on opposing walls of an inkjet cartridge reservoir by six pressure regulators similar to pressure regulator 130, which use a bow or leaf spring including two diamond-shaped strips of metal and opposing plates of similar material. The bow or leaf spring and opposing plates are made of SUS310, 3 / 4 hardness stainless steel. Each diamond-shaped strip of the spring is 0.12 millimeters (mm) thick, with a first diagonal measuring 4 centimeters and a second diagonal measuring 5 centimeters. Each opposing plate of the pressure regulator is 0.18 mm thick, 62.8 centimeters long, and 31.5 centimeters wide. + 1.5 centimeters. Table 1 shows the spring force when the spring height (or gap between plates) is 6 mm, 10 mm, and 16 mm.

[0016] [Table 1]

[0017] Figure 7 graphically depicts the backpressure or negative pressure of the pressure regulators of the six inkjet cartridges described with reference to Table 1. 0 mL to 45 mL indicates the air consumption in the cartridge (assumed to be the same as the ink consumption). "0 mL" indicates a state in which the reservoir is filled with air (simulating ink). Five mL of air is removed with a syringe and the backpressure is measured. "inH20" is the backpressure measured by the manometer at each consumption level. The backpressure is graphed to show the pressure curve. Each cartridge exhibited a backpressure ranging from 1 inch of water column to 18 inches of water column as the volume of its respective reservoir increased from 0 milliliters to 45 milliliters. The results are also shown in Table 2.

[0018] [Table 2]

[0019] FIG. 8 is a graph of the force exerted on opposing walls of the reservoirs of six inkjet cartridges (numbers 15-20) by a pressure regulator similar to pressure regulator 130, which uses a bow or leaf spring including two diamond-shaped strips of polyethylene terephthalate (PET) and opposing plates of similar material. The pressure regulator includes a spring where each diamond-shaped strip has a first diagonal of 4 cm and a second diagonal of 5 cm. Each strip of the spring is 0.4 mm thick. Each opposing plate of the pressure regulator is 0.4 mm thick, 6.2 cm long, and 4.5 cm wide.

[0020] FIG. 9 shows a graph of the backpressure or negative pressure for three pressure regulators (springs 15, 16, and 17) described with reference to FIG. 8 that use bow or leaf springs containing two diamond-shaped strips of polyethylene terephthalate (PET), and three pressure regulators (springs 5, 6, and 7) described with reference to FIG. 7 and Tables 1 and 2 that use metal bow or leaf springs containing two diamond-shaped strips. As in FIG. 7, 0 mL to 45 mL indicates the air consumption in the cartridge (assumed to be the same as ink consumption). FIG. 9 shows that three pressure regulators similar to pressure regulator 130 that use bow or leaf springs containing two diamond-shaped strips of polyethylene terephthalate (PET) and opposing plates of similar material achieved backpressures between 1 inch and 12 inches of water column over a reservoir volume range of 0 milliliters to 45 milliliters. Three metal pressure regulators similar to pressure regulator 130 achieved similar backpressure results.

[0021] FIG. 10A shows a graph of the force exerted on opposing walls of an inkjet cartridge by five pressure regulators similar to pressure regulator 130, each including two diamond-shaped strips of polycarbonate (PC) or polypropylene (PP) and opposing plates of similar material, each using a bow or leaf spring having the dimensions set forth in Table 3. FIG. 10A shows the spring force when the height of each spring (or the gap between the plates) is different. FIG. 10B shows a graph of the force exerted on opposing walls of an inkjet cartridge by eight pressure regulators similar to pressure regulator 130, each including two diamond-shaped strips of polypropylene (PP) or polyvinyl chloride (PVC) and opposing plates of similar material, each using a bow or leaf spring having the dimensions set forth in Table 3. FIG. 10B shows the spring force when the height of each spring (or the gap between the plates) is different.

[0022] [Table 3]

[0023] 11A and 11B show graphs of the backpressure or negative pressure for the five inkjet cartridges described with reference to FIGS. 10A and 10B. The results are shown in Table 4. The backpressure for each cartridge achieved between 1 inch and 12 inches of water column over a reservoir volume range of 0 milliliters to 45 milliliters, except for two pressure regulators made of PVC material, which achieved backpressures of 15.82 inches and 20.09 inches of water column at a reservoir volume of 45 milliliters.

[0024] [Table 4]

[0025] The above description describes a pressure regulator with a bow or leaf spring comprising two diamond-shaped strips of polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), or polyvinyl chloride (PVC) and opposing plates of similar material. It is understood that other non-metallic materials, particularly polymers, can be substituted. Representative examples of spring materials include those that are inert to the solution contained in the inkjet cartridge reservoir, have a modulus of elasticity between 0.5 gigapascals (GPa) and 8 GPa according to ASTM D638 or ISO 527-1:2012, and maintain a relatively constant spring force at different spring heights so that the pressure regulator 130 can maintain subatmospheric or negative pressure in the inkjet cartridge. Additionally, while a bow or leaf spring is described as part of the pressure regulator, it is understood that various shapes and types of non-metallic (e.g., polymeric) springs are available. Suitable spring shapes and types include springs that release energy, ideally with a fairly consistent energy release at different spring heights. Examples include compression springs. U.S. Patent No. 5,325,119 describes a pressure regulator for an inkjet cartridge that includes a wire spring bent into a generally serpentine configuration. The pressure regulator has a variable spring function, and the amount of force required to collapse the regulator is somewhat linear, except that the force required for the last few millimeters of movement is less than prior art designs. Non-metallic (e.g., polymeric), inert plastic-type serpentine spring pressure regulators and pressure regulators with similar variable spring functions are also contemplated herein.

[0026] Aspects The following are aspects of the present invention.

[0027] Aspect 1 a reservoir operable to contain a solution; a pressure regulator disposed within the reservoir; The pressure regulator is made of non-metallic material, suitable for inkjet cartridges.

[0028] Aspect 2 2. The inkjet cartridge of embodiment 1, wherein the non-metallic material of the pressure regulator is made of a polymer material.

[0029] Aspect 3 3. The inkjet cartridge of claim 1 or 2, wherein the pressure regulator comprises a spring made of a polymer material having a glass transition temperature between -120°C and 180°C.

[0030] Aspect 4 The inkjet cartridge of embodiment 3, wherein the spring is a bow spring or a leaf spring.

[0031] Aspect 5 An inkjet cartridge as described in aspect 3 or 4, wherein the pressure regulator comprises a first plate and a second plate, and the spring is coupled to a first side of the first plate and a first side of the second plate so as to be positioned between the first plate and the second plate.

[0032] Aspect 6 An inkjet cartridge according to any one of aspects 1 to 5, further comprising a casing defining an interior volume, and first and opposing second walls defining a reservoir within the interior volume.

[0033] Aspect 7 An inkjet cartridge as described in embodiment 6, wherein the pressure regulator comprises a first plate and a second plate, the spring is coupled to a first side of the first plate and a first side of the second plate so as to be positioned between the first plate and the second plate, the second side of the first plate is coupled to the first wall, and the second side of the second plate is coupled to the second wall.

[0034] Aspect 8 8. The inkjet cartridge according to any one of Aspects 1 to 7, wherein the non-metallic material of the pressure regulator is made of polyethylene terephthalate.

[0035] Aspect 9 Aspect 8. The inkjet cartridge according to any one of Aspects 1 to 7, wherein the non-metallic material of the pressure regulator is made of polycarbonate, polypropylene, or polyvinyl chloride.

[0036] Aspect 10 Aspect 8. The inkjet cartridge according to any one of Aspects 1 to 7, wherein the non-metallic material of the pressure regulator is made of nylon, high-density polyethylene, low-density polyethylene, or polyester.

[0037] Aspect 11 An inkjet cartridge as described in any of aspects 5 to 10, further comprising a frame coupled to the inner wall of the casing and conforming to the outer periphery of the casing, wherein a first wall is coupled to a first side of the frame and a second wall is coupled to an opposite second side of the frame such that the frame, the first wall and the second wall define a reservoir volume.

[0038] Aspect 12 12. The inkjet cartridge of embodiment 11, further comprising at least one filter coupled to the frame within the reservoir volume, the at least one filter being made of a non-metallic material.

[0039] Aspect 13 13. The inkjet cartridge according to any one of aspects 6 to 12, wherein the first wall and the second wall are made of a flexible, non-elastic material and a non-metallic material, respectively.

[0040] Aspect 14 14. The inkjet cartridge of embodiment 13, wherein the first wall and the second wall are comprised of a polymer that is chemically inert to the solution selected to be contained in the reservoir.

[0041] Aspect 15 15. The inkjet cartridge of embodiment 14, wherein the polymer comprises a coating on the first wall and a coating on the second wall.

[0042] Aspect 16 16. The inkjet cartridge according to any one of aspects 6 to 15, further comprising a stopper disposed between the outside of the casing and the reservoir, the stopper being made of a non-metallic material.

[0043] Aspect 17 17. The inkjet cartridge of any one of embodiments 1-16, further comprising a printhead in fluid communication with the reservoir.

[0044] Aspect 18 a casing defining an interior volume; a first wall and an opposing second wall defining a reservoir within the interior volume; and a pressure regulator disposed within the reservoir; The inkjet cartridge, wherein the pressure regulator includes a spring made of a non-metallic material.

[0045] Aspect 19 An inkjet cartridge as described in embodiment 18, wherein the pressure regulator further includes a first plate and a second plate each constructed of a non-metallic material, and the spring is coupled to a first side of the first plate and a first side of the second plate so as to be positioned between the first plate and the second plate.

[0046] Aspect 20 20. The inkjet cartridge of claim 18 or 19, wherein the spring is made of a polymer material having a glass transition temperature between -120°C and 180°C.

[0047] Aspect 21 21. The inkjet cartridge according to any one of aspects 18 to 20, wherein the spring is a bow spring or a leaf spring.

[0048] Aspect 22 22. The inkjet cartridge of any one of embodiments 18-21, further comprising a printhead in fluid communication with the reservoir.

[0049] While particular aspects of the invention have been described in detail, it will be appreciated that those skilled in the art may develop various modifications and alternatives to these details in light of the overall teachings of this disclosure. Accordingly, the particular arrangements disclosed are intended to be illustrative only and not limiting as to the scope of the invention, which is to be accorded the full breadth and scope of the invention in accordance with the appended claims and embodiments and any equivalents thereof.

Claims

1. a reservoir operable to contain a solution; a pressure regulator disposed within the reservoir; The pressure regulator is made of non-metallic material, suitable for inkjet cartridges.

2. The inkjet cartridge of claim 1 , wherein the non-metallic material of the pressure regulator comprises a polymeric material.

3. 2. The inkjet cartridge of claim 1, wherein the pressure regulator comprises a spring made of a polymer material having a glass transition temperature between -120°C and 180°C.

4. 4. The ink jet cartridge of claim 3, wherein the spring is a bow spring or a leaf spring.

5. 4. The inkjet cartridge of claim 3, wherein the pressure regulator comprises a first plate and a second plate, and the spring is coupled to a first side of the first plate and a first side of the second plate so as to be disposed between the first plate and the second plate.

6. 10. The inkjet cartridge of claim 1, further comprising a casing defining an interior volume, and first and opposing second walls defining said reservoir within said interior volume.

7. 7. The inkjet cartridge of claim 6, wherein the pressure regulator comprises a first plate and a second plate, the spring being coupled to a first side of the first plate and a first side of the second plate so as to be disposed between the first plate and the second plate, the second side of the first plate being coupled to the first wall, and the second side of the second plate being coupled to the second wall.

8. 10. The ink jet cartridge of claim 1, wherein the non-metallic material of the pressure regulator comprises polyethylene terephthalate.

9. 10. The ink jet cartridge of claim 1, wherein the non-metallic material of the pressure regulator is made of polycarbonate, polypropylene, or polyvinyl chloride.

10. 10. The ink jet cartridge of claim 1, wherein the non-metallic material of the pressure regulator is made of nylon, high density polyethylene, low density polyethylene, or polyester.

11. 7. The inkjet cartridge of claim 6, further comprising a frame coupled to an inner wall of the casing and conforming to the shape of an outer periphery of the casing, the first wall being coupled to a first side of the frame and the second wall being coupled to an opposite second side of the frame such that the frame, the first wall and the second wall define a volume of the reservoir.

12. 12. The inkjet cartridge of claim 11, further comprising at least one filter coupled to said frame within said volume of said reservoir, said at least one filter being made of a non-metallic material.

13. 7. The ink jet cartridge of claim 6, wherein said first wall and said second wall are made of a flexible, non-elastic, and non-metallic material, respectively.

14. 14. The inkjet cartridge of claim 13, wherein said first wall and said second wall are comprised of a polymer that is chemically inert to the solution selected to be contained within said reservoir.

15. 15. The inkjet cartridge of claim 14, wherein the polymer includes a coating on the first wall and a coating on the second wall.

16. 7. The ink jet cartridge of claim 6, further comprising a stopper disposed between the exterior of said casing and said reservoir, said stopper being made of a non-metallic material.

17. The inkjet cartridge of claim 1 further comprising a printhead in fluid communication with said reservoir.

18. a casing defining an interior volume; a first wall and an opposing second wall defining a reservoir within the interior volume; a pressure regulator disposed within the reservoir; The inkjet cartridge, wherein the pressure regulator includes a spring made of a non-metallic material.

19. 20. The inkjet cartridge of claim 18, wherein the pressure regulator further comprises a first plate and a second plate each constructed of a non-metallic material, and wherein the spring is coupled to a first side of the first plate and a first side of the second plate so as to be disposed between the first plate and the second plate.

20. 18. The ink jet cartridge of claim 17, wherein the spring is made of a polymer material having a glass transition temperature between -120°C and 180°C.

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