Printhead die cap

Abstract

In one example according to the present disclosure, a printhead lid system is described. The printhead lid system includes a lid having an elastomeric seal for enclosing a printhead die on a print cartridge. The printhead lid system also includes a variable force lidding station for holding the lid. The variable force lidding station moves the lid to 1) a first position in which the lid exerts a first force on a substrate having the printhead die disposed thereon and 2) a second position in which the lid exerts a second force on the substrate. In an example, the second force is greater than the first force. The printhead lid system also includes a control system for lifting the lid from an unlidded position through the first position and the second position.

Description

BACKGROUND

[0001] A print cartridge is a component of a printing system that ejects droplets of printing fluid, such as ink, onto a substrate to form text and / or images. A print cartridge includes a plurality of printheads. Each printhead includes a plurality of nozzles. In the nozzles, a small amount of printing fluid can be held in an ejection chamber. An actuator, such as a thermal actuator, can be activated to expel the printing fluid through an opening onto a substrate. A controller selectively activates the actuator at predetermined times in order to form text and / or images on the substrate. BRIEF DESCRIPTION OF DRAWINGS

[0002] The accompanying drawings illustrate various examples of the principles described herein and are a part of the specification. The illustrated examples are given solely for illustration and do not limit the scope of the claims.

[0003] Figure 1 is a block diagram of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0004] Figure 2 is an isometric view of a printing system with a variable force printhead cover in accordance with examples of the principles described herein.

[0005] Figure 3 is an isometric view of a print cartridge with a variable force printhead cover in accordance with examples of the principles described herein.

[0006] Figure 4 is an isometric view of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0007] Figure 5 is an exploded view of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0008] Figure 6 is a flowchart of a method for capping a print cartridge in accordance with examples of the principles described herein.

[0009] Figure 7 is an isometric view of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0010] Figure 8 is an isometric view of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0011] Figure 9 is an isometric view of a printhead cover system with a variable force printhead cover in accordance with examples of the principles described herein.

[0012] Figure 10Isometric view of a printhead cover system with a variable force printhead cover according to examples of the principles described herein.

[0013] Figure 11 Isometric view of a printhead cover system with a variable force printhead cover according to examples of the principles described herein.

[0014] Figure 12 Exploded view of a cover and a non-linear spring according to examples of the principles described herein.

[0015] Figure 13 Cross-sectional view of a cover and a non-linear spring according to examples of the principles described herein.

[0016] In all of the drawings, like reference numerals refer to like parts throughout the several views. The drawings are not necessarily to scale and the size of some parts can be exaggerated to illustrate details of the examples shown; furthermore, some parts can be shown exaggerated in number so as to illustrate an example and / or an embodiment; the drawings are intended as illustrative examples and / or embodiments and not as limitations on the description. DETAILED DESCRIPTION

[0017] Printing involves depositing a print agent (such as ink, toner, etc.) in a pattern on a substrate to form text and / or images. A printhead is a component of a printing system that includes a plurality of ejectors. Through these ejectors, a print fluid such as ink, optimizer, and fusing agent, etc. is ejected. Specific examples of devices that rely on printheads include inkjet printers, multi-function printers (MFPs), and additive manufacturing equipment (also known as 3D printers). For example, in additive manufacturing equipment, a fluid ejection system dispenses a fusing agent. The fusing agent is deposited on a build material, which the fusing agent promotes to harden to form a three-dimensional product.

[0018] Other printheads dispense ink on a two-dimensional print medium such as paper. For example, during inkjet printing, ink is directed to a printhead die. Depending on the content to be printed, the device on which the printhead is disposed decides the time and location at which ink drops will be released / ejected onto the print medium. In this manner, the printhead releases a plurality of ink drops on a predetermined area to produce a representation of the image content to be printed. In addition to paper, other forms of print media can also be used.

[0019] Accordingly, as described above, the systems and methods described herein can be implemented in two-dimensional printing, i.e., depositing a fluid on a substrate; and in three-dimensional printing, i.e., depositing a fusing agent or other functional agent on a material base to form a three-dimensional printed product.

[0020] Additionally, the systems and methods described herein can be implemented in printing systems that contain different types of printheads. For example, the ejectors can be firing resistors. A firing resistor heats in response to an applied voltage. As the firing resistor heats, a portion of the fluid in the ejection chamber vaporizes to generate a bubble. This bubble pushes fluid out of the opening and onto the substrate. As the vaporized fluid bubble bursts, fluid is drawn into the ejection chamber from a channel that connects the ejection chamber to a fluid feed slot, and the process repeats. In this example, the printhead can be a thermal inkjet (TIJ) printhead.

[0021] In another example, the ejectors can be piezoelectric devices. Upon application of a voltage, a piezoelectric ejector changes shape, which generates a pressure pulse in the ejection chamber that pushes fluid out of the opening and onto the substrate. In this example, the printhead can be a piezoelectric inkjet (PIJ) printhead.

[0022] While such printheads no doubt advance the field of precise fluid delivery, certain conditions can affect their effectiveness. For example, inkjet printing systems rely on liquid ink that is ejected from the printhead. To maintain proper operation of the ejectors, the nozzles of the printhead should be maintained under specific environmental conditions. For example, low or high humidity environments can cause the nozzles to not operate properly. As another example, if the printhead remains exposed for a duration of time without use, the printing fluid, such as ink, can crust over the nozzles, thereby affecting their intended use or operation.

[0023] Accordingly, the present specification describes a printhead cap system for maintaining a controlled environment. In particular, the present printhead cap system includes an elastomeric cap that can be supported by a compression spring. The elastomeric cap presses against the printhead around an area of the substrate that includes a die of the printhead that includes a nozzle to provide a seal on the surface of the printhead around the nozzle. Such a cap can prevent the nozzle from drying out and can also provide a controlled environment with respect to certain environmental parameters, such as humidity and pressure.

[0024] The printhead cap system also accommodates different capping forces. For example, when not in use, i.e., when not actively printing, the printhead cap system can exert a first force to prevent the nozzle from drying out and to maintain desired environmental conditions. At other periods of time, the capping force can be increased. For example, the print cartridge can be “primed” to expel air from the print cartridge.

[0025] priming event. For example, when air is in the jetting chamber or nozzle, air is ejected instead of fluid, which can result in a decrease in fluid being ejected. This can result in uneven fluid distribution on the substrate, which can result in uneven coloring or formation of text and / or images. Additionally, the ingested air can also shorten the life of the cartridge, such as by destroying the thermal actuators, such as when air is close to the thermal actuators of the jetting chamber when the actuators are fired resulting in a thermal overrun. Air ingestion can occur in any case. For example, in some printing systems, the cartridges are not discarded after use, but are refilled by a fluid tank inside the printing system. Such printing systems can greatly increase the output of the cartridges over their lifetime.

[0026] In such continuous fluid supply systems, air bubbles can be generated in the fluid supply line and, thus, can cause air pockets in the reservoir and nozzle during jetting. As another example, air can be ingested into the jetting chamber through openings in the nozzle due to negative pressure generated when the TIJ or PIJ jetter is primed.

[0027] In any case, the printing system can include a priming system to remove air from the ink delivery system and / or the cartridge. During priming, a lid is placed over the printhead die and a vacuum can generate a negative pressure over the nozzles to pull air through the nozzles. To ensure a seal is maintained during the priming event, higher lid forces can be required. That is, the lid forces used when the printing system is not printing can not be sufficient to maintain a seal during priming when a negative pressure is pulled. In contrast, the lid forces expected during priming can cause temporary or permanent damage to the printhead if used during more frequent non-printing and non-priming intervals. That is, the printhead can include certain fragile components, such as components within the flexible circuit on the underside of the cartridge. Higher lid forces provided by thick elastomeric walls can cause the printhead to deflect and / or permanently deform. If higher lid forces are used during priming, which are used during these more frequent non-priming lid intervals, these components of the printhead can be temporarily or permanently damaged. As a result, printing quality, cartridge and printhead life can all be affected.

[0028] Accordingly, this specification describes a multi-force lid system. In particular, a printhead lid system can apply a first force when the printing system is idle but not in a priming cycle. In the event that a priming cycle is initiated, the printhead lid system can apply a second force that is greater than the first force and ensures that a seal around the nozzles is maintained during the priming event. In other words, rather than providing a lid system with only one lidding force (whether that lidding force is a non-prime lidding force or a higher value lidding force), this specification describes a multi-force printhead lid system. When the print cartridge is not activated, it is lidded by the first force and placed under a higher lidding force when a priming event is triggered. Since priming events can be infrequent, e.g., about twenty times over the course of a print cartridge’s lifetime, exposure of the printhead to the higher lidding force is reduced. This multi-variable lidding force can be implemented in a number of ways, as described in the examples and accompanying drawings below.

[0029] In particular, this specification describes a printhead lid system. The printhead lid system includes a lid with an elastomeric seal for surrounding a printhead die on a print cartridge. The printhead lid system also includes a variable force lidding station for holding the lid. The variable force lidding station moves the lid to 1) a first position in which the lid exerts a first force on a substrate on which the printhead die is disposed and 2) a second position in which the lid exerts a second force on the substrate. In an example, the second force is greater than the first force. The printhead lid system also includes a control system for lifting the lid from an unlidded position through the first position and the second position.

[0030] This specification also describes a method. According to the method, a print cartridge of a printing system is aligned with a variable force lidding station. A lid including an elastomeric seal for surrounding a printhead die of the print cartridge is raised to a first position to deform the elastomeric seal against an underside of the print cartridge. The lid is further raised to a second position to further deform the elastomeric seal against the underside of the print cartridge.

[0031] This specification also describes a printing system. The printing system includes a print cartridge for ejecting a fluid. The print cartridge is movable between a printing zone and a lidding zone adjacent to the printing zone. The printing system also includes a printhead lid system. The printhead lid system includes a lid with an elastomeric seal for surrounding a printhead die on a print cartridge and a variable force lidding station. In this example, the variable force lidding station includes a lid plate for holding the lid and moving in a first direction to interact with a prime shuttle ramp to lift the lid to a first position and a prime shuttle for holding the lid plate and moving in a second direction to interact with a base ramp to lift the lid to a second position. The printing system also includes a control system for moving the lid plate and the prime shuttle in the first direction and the second direction, respectively.

[0032] This system and method 1) provides different capping forces when the printing system is in different states, i.e., an idle but not primed state and a primed state; 2) avoids repeated and long exposure to high capping forces on the print head; 3) provides a controlled environment for the print head when not in use; and 4) prevents the nozzles from drying out. However, it is contemplated that the system and method disclosed herein can address other issues and deficiencies in many technical fields.

[0033] Turning now to the drawings, Figure 1 is a block diagram of a print head capping system (100) with a variable force print head cap (102) according to an example of the principles described herein. As described herein, the print head capping system (100) is used to cap a print head of a print cartridge. As used in this specification and the appended claims, the term print cartridge can refer to a fixed print cartridge (such as a print bar) or a scanning cartridge. In the example of a fixed print cartridge, a variable force capping station (104) can move to align the cap (102) underneath the stationary print cartridge. In another example, the print cartridge can be a scanning cartridge that is coupled to a carriage and moves over a substrate. In this example, the carriage can move the print cartridge (102) into position on the cap (102). At this point, the cap (102) can be raised to provide the capping functionality described.

[0034] In either case, the print head capping system (100) includes a cap (102) that has an elastomeric seal for surrounding a print head die on a print cartridge. When capped, the elastomeric seal portion of the cap (102) deforms against the substrate and around the print head die. In doing so, the cap (102) provides a controlled pressure and humidity environment in the area around the nozzles so that the nozzles do not dry out and are not negatively affected by undesirable environmental conditions.

[0035] As described above, the cap (102) is disposed on a variable force capping station (104) that holds and moves the cap (102). In particular, the print head can be on an underside of the print cartridge. After the cap (102) is aligned underneath the print cartridge to surround the print head die, the variable force capping station (104) can raise the cap (102) to various capping positions. In doing so, the variable force capping station (104) can include a platform on which the cap is disposed. A motor coupled to the platform can operate to raise or lower the platform. That is, the variable force capping station (104) can include any number of gears, belts, or other mechanisms to convert the rotational motion of the motor to translational motion.

[0036] In particular, the variable force capping station (104) can move the cap to a first position in which the cap (102) exerts a first force on the substrate on which the printhead die is disposed. At a different point in time, such as during a priming event, or in anticipation of a priming event, the variable force capping station (104) can move the cap (102) to a second position in which the cap exerts a second force on the substrate. In particular examples, the first and second positions can be defined in a vertical direction. That is, the variable force capping station (104) can raise the cap (102) to the first position, and can also raise the cap (102) to the second position.

[0037] As noted above, the second force can be greater than the first force, and can be used during a priming of the print cartridge. That is, the cap (102) can be in the first position when the print cartridge is idle or inactive and not in a priming cycle. When greater capping force is desired, the cap (102) can be in the second position during priming of the printhead. In this second position, the print cartridge is positioned and has sufficient sealing to accommodate priming operations.

[0038] In examples, the first capping force during idle and unprimed intervals can be 1.5 Newtons (N), while the second capping force during priming intervals can provide 3.5 N of force. As noted above, because the printhead is exposed to the greater capping force only during priming intervals, and not at other times, the printhead is exposed to headland stress for a reduced amount of time, thereby increasing printhead reliability performance.

[0039] The printhead capping system (100) also includes a control system (106) for lifting the cap (102) from an uncapped position through the first and second positions. The control system (106) can include a processor and memory to receive instructions, such as from a user, and execute the instructions to operate a motor to move the variable force capping station (104) as described above. For example, the control system (106) can receive an indication that a printing operation has terminated, and can control the motor to move the capping station (104) to raise the cap (102) to the first position. The control system (106) can also receive an instruction to perform a priming operation, and control the motor to move the capping station (104) to raise the cap (102) to the second position.

[0040] As described above, the control system (106) may include various hardware components, including processors and memory. The processor may include a hardware architecture that retrieves executable code from memory and executes the executable code. As a specific example, the control system (106) described herein may include computer-readable storage media, processors, application-specific integrated circuits (ASICs), semiconductor-based microprocessors, central processing units (CPUs), field-programmable gate arrays (FPGAs), and / or other hardware devices.

[0041] The memory may include a computer-readable storage medium that may contain or store computer-usable program code for use by or in connection with an instruction execution system, device, or apparatus. The memory may be of various types, including volatile and non-volatile memory. For example, the memory may include random access memory (RAM), read-only memory (ROM), optical disks, and magnetic disks. When executed by the control system (106), the executable code enables the control system (106) to at least implement the functions of the moving variable-force sealing station (104) and the cover (102).

[0042] Figure 2 This is an example of a variable force printing head cap based on the principles described in this article. Figure 1 An isometric view of the printing system (208) (102). As described above, the printing system (208) may have a fixed print cartridge (212) or may have a scanning print cartridge (212). Figure 2 An example of a scanning print box (212) is depicted. Figure 2 In the example depicted, the print cartridge (212) can scan over the print area (210) in the direction (218) indicated by the arrow to deposit print fluid onto the substrate. While being printed on, the substrate moves to the output tray in the direction (216) indicated by the arrow.

[0043] In this example, during idle time and during a startup event, the print cartridge (212) can be transported from the print area (210) to the variable force capping station (104). Once set on the variable force capping station (104), capping and / or startup can be performed as described below. Although Figure 2 A specific example of a printing system (208) has been described, but other printing systems (208) (such as printing systems implementing a fixed print cassette (212)) may also include the printhead system described herein.Figure 1 (100). In these examples, the variable force capping station (104) can be transported to align with the fixed printing box (212).

[0044] Figure 3 This is an example of a variable force printing head cap based on the principles described in this article. Figure 1 Isometric views of print boxes (212-1, 212-2) of the printing system (102). As mentioned above, print box (212) can refer to the printing system ( Figure 2 , 208) is a component that retains fluid and includes a printhead from which fluid is ejected. In some examples, the print cartridge (212) can be drawn from the printing system ( Figure 2 Removed from (208) so that they can be discarded when their respective storage is empty. In other examples, the printing system ( Figure 2 , 208) may include a larger print fluid reservoir that continuously resupply print fluid to the print cartridge (212).

[0045] In either example, the printing system ( Figure 2 ,208) may include a printhead cover system ( Figure 1 The printhead cap system includes a printhead cap (100), Figure 1 ,102). Figure 3 The image depicts a printhead cover including a cover body (318) and an elastomeric seal (320). Figure 1 (102). The elastomeric seal (320) can enclose the nozzle region of the substrate of the printhead die. That is, the elastomeric seal (320) can form a continuous path that, once against the substrate, surrounds the printhead nozzle to create a seal, thereby providing controlled environmental conditions around the nozzle when not in use and maintaining the seal during startup.

[0046] As described above, the elastomeric seal (320) can be formed of a compliant material (such as rubber) that deforms in response to an applied force. Thus, when the variable force sealing station ( Figure 1 ,104) Lifting cover ( Figure 1 When , 102), the elastomeric seal (320) deforms against the substrate to form a closed environment around the printhead die.

[0047] Figure 4 This is an example of a printing system based on the principles described in this article. Figure 2 An isometric view of a portion of (208). As described above, the printing system ( Figure 2 , 208) includes a printing cartridge (212) for jetting fluid. As described above, in such Figure 2 In some examples depicted, the print box (212) can be placed in the print area ( Figure 2,210) and the capping area adjacent to the printing area ( Figure 2 Move between , 210). Figure 4 It also describes elastomeric seals ( Figure 3 The cover of (320) is an elastomeric seal that surrounds the printhead die on the print cartridge (212).

[0048] As mentioned above, the printing system ( Figure 2 , 208) may include a mechanism for aligning the print cartridges (212-1, 212-2) with the printhead variable force capping station (104). Figure 4 The arrangement of these components is described. Figure 4 Various components are also depicted that can be implemented to facilitate the printhead die lifter against the print cartridge (212). Figure 1 (102). Specifically, the variable force capping station (104) may include a cap plate (422) that holds the cap (102) and moves in a first direction (216), which may be similar to the direction of medium travel. The cap plate (422) may include pins that interact with a tilting groove in the starting shuttle (424) as the cap plate (422) moves in the first direction. The interaction between the cap plate (422) pins and the tilting groove of the starting shuttle (424) provides the cap (102) with a force that holds the cap (102) in place. Figure 1 , 102) is a mechanism that moves the print box (212) through different positions.

[0049] Figure 4 A starter shuttle (424) is also depicted, which holds the cover plate (422) and moves in a second direction (218), which may be perpendicular to the direction of media travel. The starter shuttle (424) may include pins that interact with an inclined groove in the base (426) as the starter shuttle (424) moves in the second direction. The interaction between the pins of the starter shuttle (424) and the inclined groove in the base (426) provides the ability to move the cover plate relative to the print cartridge (212). Figure 1 ,102) through another mechanism in different locations.

[0050] Note that any of these mechanisms can be used independently to cover ( Figure 1 , 102) moves toward the corresponding print box (212). In the example, these mechanisms can be used in combination to move the cover ( Figure 1 , 102) moves to a different position relative to the printing box (212). Figure 4 A control system (106) for moving the cover plate (422) and the starter shuttle (424) in the first and second directions respectively is also depicted.

[0051] Figure 5This is an exploded view of a printhead system (100) with a variable force printhead cap (102) as an example of the principles described herein. Specifically, Figure 5 It describes the corresponding printing box ( Figure 2 Align and press the caps (102-1, 102-2) against it. Figure 5 The relationship between the cover plate (422), the starter shuttle (424), and the base (426) as described above is also depicted. Figure 5 Springs (528-1, 528-2) are also depicted, these springs being used in elastomeric seals ( Figure 3 ,320) and printing box ( Figure 2 Force is generated between the printhead dies of (212). In addition to the two mechanisms previously described (i.e., the interaction between the cover pin / starting shuttle tilt groove and the interaction between the starting shuttle pin / base tilt groove), spring 528 can provide an additional mechanism to apply force to push the cover 102 against the print cartridge. Figure 2 ,212).

[0052] That is, the spring (528) can be a nonlinear spring with different spring constants along its length. Therefore, the first portion with the first lower spring constant can be compressed first to compress the elastomeric seal ( Figure 3 ,320) and printing box ( Figure 2 A first force is provided between (212). Upon further elevation, a second portion with a second, higher spring constant can be compressed to provide force to the elastomeric seal ( Figure 3 ,320) and printing box ( Figure 2 A second force is provided between the cover (102) and the cover plate (422) of the variable force sealing station (104). That is, the variable force sealing station (104) may include a nonlinear spring (528) disposed between the cover (102) and the cover plate (422) of the variable force sealing station (104). Compression of a first portion of the nonlinear spring (528) provides the first force, while compression of a second portion of the nonlinear spring (528) provides the second force. (The following is in conjunction with...) Figure 12 More details are provided regarding the nonlinear spring (528). Overall, Figure 7 to Figure 9 Depicting the use of lid ( Figure 1 ,102) The first mechanism for moving toward the spring, Figure 10 and Figure 11 The second mechanism was described, and Figure 12 and Figure 13 A third mechanism is described. Each of these mechanisms can be used individually or collectively to move the cap (102) through a series of positions, in which the cap (102) presses against the printhead die with different forces at each position.

[0053] Figure 6An example of a printing box for sealing, based on the principles described in this article. Figure 2 The flowchart of method (600) of 212). According to method (600), the printing box ( Figure 2 ,212) and variable force sealing station ( Figure 1 Alignment (box 601) with the printing system (104). In some examples, this may include aligning the printing system ( Figure 2 ,208) printing box ( Figure 2 ,212) from the printing area ( Figure 2 ,210) transported to the adjacent printing area ( Figure 2 ,210) variable force sealing station ( Figure 1 ,104). Once with the print box ( Figure 2 Align 212) with the cover ( Figure 1 , 102) can be raised (box 602) to a first position so that the cover ( Figure 1 102) elastomeric seals Figure 3 ,320) against the printer box ( Figure 2 The lower side of the print box (212) is deformed. As described above, when the print box ( Figure 2 ,212) is not activated, but not during the startup cycle, cover ( Figure 1 , 102) can remain in this position, thereby applying a first force, for example, 1.5N.

[0054] The lid can be Figure 1 , 102) further raise (frame 603) to the second position, so that the cover ( Figure 1 102) elastomeric seals Figure 3 ,320) against the printer box ( Figure 2 The lower side of (212) is further deformed. As described above, when the printing box ( Figure 2 When 212) is in the starting position, the cover ( Figure 1 , 102) can remain in this position, thereby applying a second force, for example, 4.5N.

[0055] Figure 7 This is an example of a printhead system with a variable force printhead (102) based on the principles described herein. Figure 1 An isometric view (100). For simplicity, in Figure 7 In the figure, an example of the cover (102) is depicted with reference numerals. As described above, Figure 7 to Figure 9 The first mechanism is depicted, in which the cover (102) is raised to abut against the printing cartridge ( Figure 2 , 212) Deformation. Specifically, in this example, cover plate 422 includes pins (732-1, 732-2) for interacting with the inclined slots (730-1, 730-2) of starter shuttle 424.

[0056] In this example, the tilted slots (730-1, 730-2) in the priming shuttle (424) have three stable positions. First, Figure 7 The cover plate (422) is depicted in a first stable position. Figure 8 The cover plate (422) is depicted in a second stable position, and Figure 9 The cover plate (422) is depicted in a third stable position. In an example, the cover (102) can be in the second stable position when the print cartridge (212) is in an idle and non-priming interval, and the cover (102) can be in the third stable position when the print cartridge (212) is in a priming interval. In another example, the cover (102) can be in the third stable position when the print cartridge (212) is in an idle and non-priming interval, and the cover (102) can be in the Figure 2 position depicted in FIG. 21B. Figure 2 Figure 2 Figure 2 Figure 11

[0057] As depicted in FIG. 21A, the cover plate (422) is translated in a first direction (216). As the slots (730-1, 730-2) are tilted, the cover plate (422) is also raised in a vertical direction 734 indicated by the arrow. In the example depicted in FIG. 21B, the control system (107) moves the cover plate (422) in the first direction (216) such that the interaction between the pins (732-1, 732-2) on the cover plate (422) and the tilted slots (730) in the priming shuttle (424) moves the cover plate (422) and the cover (102) upward toward the print cartridge (212). Figure 7 to Figure 9 Figure 7 to Figure 9 Figure 1 Figure 2

[0058] Figure 8 is an isometric view of a printhead cover system (100) having a variable force printhead cover (102) in accordance with an example of the principles described herein. As depicted in FIG. 20A, the control system (106) has translated the cover plate (422) in a first direction (216), and due to the interaction between the pins (732-1, 732-2) in the cover plate (422) and the tilted slots (730-1, 730-2) in the priming shuttle (424), the cover plate (422) is not only translated in the first direction (216), but is also in a higher position along a vertical direction (734). Figure 1 Figure 1 Figure 8 Figure 1

[0059] Figure 9 ​​​​​​​​​​​​This is an example of a variable force printing head cap based on the principles described in this article. Figure 1 ,102) printhead cap system ( Figure 1 An isometric view (100). Figure 9 As described, the control system ( Figure 1 , 106) has further translated the cover plate (422) in the first direction (216), and due to the interaction between the pins (732-1, 732-2) in the cover plate (422) and the inclined grooves (730-1, 730-2) in the starting shuttle (424), the cover plate (422) is not only translated in the first direction (216), but also in a position even higher along the vertical direction (716). Note that in Figure 7 to Figure 9 In the example depicted, the starter shuttle (424) is translated into coupling with the base (426) in a first direction (216). That is, the starter shuttle (424) has not yet moved relative to the base (426) along this first direction (216) while the cover plate (422) has already moved relative to the starter shuttle (424) and the base (426) along the first direction (216).

[0060] Figure 10 This is an example of a printhead system with a variable force printhead (102) based on the principles described herein. Figure 1 An isometric view (100). As described above, Figure 10 and Figure 11 A second mechanism is depicted, in which the cover (102) is raised to abut against the printing cartridge ( Figure 2 , 212) Deformation. Specifically, in this example, the starter shuttle (424) includes pins (732-3, 732-4) for interacting with the inclined slots (730-3, 730-4) of the base (426). In the example, when the printing cartridge ( Figure 2 When , 212) is in the idle and non-starting position, the cover (102) can be in this orientation.

[0061] like Figure 10 and Figure 11 As depicted, the starting shuttle (424) translates in a second direction (218), which is perpendicular to the first direction (216). As the slots (730-3, 730-4) tilt, the starting shuttle (424) also rises in the vertical direction (734) indicated by the arrow. Figure 10 and Figure 11 In the example shown, the control system ( Figure 1, 106) in the second direction (218) such that the interaction between the pins (732-3, 732-4) in the starter shuttle (424) and the angled slots (730-3, 730-4) in the base (426) moves the starter shuttle (424) and the lid (102) upward toward the print cartridge (208) in the second direction (218). Figure 2 , 218).

[0062] Figure 10 and Figure 11 Other components are also depicted. In particular, Figure 10 A protrusion 1036 is shown for interacting with the print cartridge (208) to slide the print cartridge (208) in the second direction (218) when the starter shuttle 424 is moved in the second direction 218. That is, the printing system (208) can include a starter station (1038) that includes a pump that generates negative pressure and a hose that is connected to the print cartridge (208). However, when in the position depicted in Figure 2 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 2 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 2 , 208) can include a starter station (1038) that includes a pump that generates negative pressure and a hose that is connected to the print cartridge (208). However, when in the position depicted in Figure 2 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 10 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 11 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 2

[0063] Figure 11 is an isometric view of a printhead capping system (100) with a variable force printhead cap (102) according to examples of the principles described herein. As depicted, the control system (106) has translated the starter shuttle (424) in the second direction (218) and, due to the interaction between the pins (732-3, 732-4) in the starter shuttle (424) and the angled slots (730-3, 730-4) in the base (426), the starter shuttle (424) not only translates in the second direction (218) but also is in a higher position along the vertical direction (734). In examples, the lid (102) can be in this orientation when the print cartridge (208) is in the primed position. Figure 1 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 1 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 11 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 1 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force. Figure 2 , 212) in the second direction (218) to further lift the print cartridge (208) to generate the desired higher capping force.

[0064] Note that in Figure 10 and Figure 11 ​In the depicted example, the cover plate (422) is translationally coupled to the priming shuttle (424) in the second direction (218). That is, the cover plate (422) has not moved relative to the priming shuttle (424) in the second direction (218) while the priming shuttle (424) has moved relative to the base (426) in the second direction (218).

[0065] Figure 12 is an exploded view of a cover (102) and a nonlinear spring (528) according to examples of the principles described herein. As described above, the nonlinear spring (528) can have different regions, each with a different spring constant. The force (F) applied to the print cartridge (212) can depend on the spring constant. For example, the spring constant of the first portion can be such that compression of the first portion results in a force of 1.5 N, and the spring constant of the second portion can be such that compression of the second portion results in an additional force of 3.5 N (F) on the print cartridge (212). The second portion can have a shorter spring compression distance than the first portion. Figure 2 Figure 2 ,212) on the print cartridge (212). For example, the first portion and the second portion can have similar dimensions. For example, the portions can have a 0.45 millimeter (mm) diameter wire and a 6.33 mm diameter spring. However, there can be more coils on the first portion, e.g., eight, than on the second portion, which can have five coils. In this example, the spring constant of the first or top portion can be 0.3 N per mm, and the spring constant of the second or bottom portion can be 0.6 N per mm.

[0066] As described above, the nonlinear spring (528) can provide a third mechanism, which can be used independently or in combination with the mechanisms described earlier, to generate multiple forces between the cover (102) and the associated print cartridge (212). For example, upon lifting of the variable force capping station (104), the interaction between the base (426) and the cover (102) can exert a first force on the print cartridge (212). As the variable force capping station (104) is lifted further, the second portion of the spring is compressed, and an additional force (albeit at a different rate) is exerted at the print cartridge (212).

[0067] As described above, the nonlinear spring (528) can provide a third mechanism, which can be used independently or in combination with the mechanisms described earlier, to generate multiple forces between the cover (102) and the associated print cartridge (212). For example, upon lifting of the variable force capping station (104), the interaction between the base (426) and the cover (102) can exert a first force on the print cartridge (212). As the variable force capping station (104) is lifted further, the second portion of the spring is compressed, and an additional force (albeit at a different rate) is exerted at the print cartridge (212). Figure 2 Figure 1 ,212) on the print cartridge (212). For example, the first portion and the second portion can have similar dimensions. For example, the portions can have a 0.45 millimeter (mm) diameter wire and a 6.33 mm diameter spring. However, there can be more coils on the first portion, e.g., eight, than on the second portion, which can have five coils. In this example, the spring constant of the first or top portion can be 0.3 N per mm, and the spring constant of the second or bottom portion can be 0.6 N per mm. Figure 4 Figure 1 As described above, the nonlinear spring (528) can provide a third mechanism, which can be used independently or in combination with the mechanisms described earlier, to generate multiple forces between the cover (102) and the associated print cartridge (212). For example, upon lifting of the variable force capping station (104), the interaction between the base (426) and the cover (102) can exert a first force on the print cartridge (212). As the variable force capping station (104) is lifted further, the second portion of the spring is compressed, and an additional force (albeit at a different rate) is exerted at the print cartridge (212). Figure 2 Figure 1 ,212) on the print cartridge (212). For example, the first portion and the second portion can have similar dimensions. For example, the portions can have a 0.45 millimeter (mm) diameter wire and a 6.33 mm diameter spring. However, there can be more coils on the first portion, e.g., eight, than on the second portion, which can have five coils. In this example, the spring constant of the first or top portion can be 0.3 N per mm, and the spring constant of the second or bottom portion can be 0.6 N per mm. Figure 2

[0068] ​​​​​Figure 13 is a cross-sectional view of the cap (102) and nonlinear spring (528) according to an example of the principles described herein. Figure 1 Specifically, Figure 13 depicts how the nonlinear spring (528) generates a force on the cap body (318) that compresses the elastomeric seal (320) against the print cartridge (212).

[0069] Such systems and methods 1) provide different capping forces when the printing system is in different states, namely an idle but not primed state and a primed state; 2) avoid repeated and prolonged exposure to high capping forces on the printhead; 3) provide a controlled environment for the printhead when not in use; and 4) prevent the nozzles from drying out. However, it is contemplated that the systems and methods disclosed herein can address other problems and deficiencies in many technical areas.

Claims

1. A printhead cover system comprising: a cover including an elastomeric seal for surrounding a printhead die on a print cartridge; a variable force capping station for holding the cover, the variable force capping station for moving the cover to: a first position in which the cover exerts a first force on a substrate on which the printhead die is disposed; and a second position in which the cover exerts a second force on the substrate, wherein the second force is greater than the first force; and a control system for lifting the cover from an uncapped position through the first position and the second position.

2. The printhead cover system of claim 1, wherein when in the second position, the print cartridge is in a position to be primed.

3. The printhead cover system of claim 1, wherein: the variable force capping station further comprises: a cover plate including a pin for interacting with a ramped slot of a priming shuttle; and the priming shuttle includes the ramped slot for interacting with the pin on the cover plate; and the control system is for moving the cover plate in a first direction such that interaction between the pin and the ramped slot moves the cover plate and the cover upward toward the print cartridge.

4. The printhead cover system of claim 3, wherein the ramped slot includes three stable positions.

5. The printhead cover system of claim 1, wherein: the variable force capping station further comprises: a cover plate for holding the cover; a priming shuttle including a pin for interacting with a ramped slot of a base; and the base includes the ramped slot for interacting with the pin on the priming shuttle; and the control system is for moving the priming shuttle in a second direction such that interaction between the pin and the ramped slot moves the priming shuttle and cover upward toward the print cartridge.

6. The printhead cover system of any of claims 3-5, wherein: the variable force capping station further comprises a non-linear spring disposed between the cover and a base of the cover plate; compression of a first portion of the non-linear spring provides the first force; and compression of a second portion of the non-linear spring provides the second force.

7. The printhead cover system of claim 6, wherein the second portion of the non-linear spring has a different length, pitch, and cross-sectional diameter than the first portion of the non-linear spring.

8. A method for capping a print cartridge comprising: aligning a print cartridge of a printing system with a variable force capping station; raising a cover to a first position to deform an elastomeric seal against an underside of the print cartridge, the cover including the elastomeric seal for surrounding a printhead die of the print cartridge; and raising the cover to a second position to further deform the elastomeric seal against the underside of the print cartridge.

9. The method of claim 8, wherein: the cover is in the first position when the print cartridge is not activated; and the cover is in the second position during a printhead priming.

10. The method of claim 8, wherein: the cover is in the first position when the print cartridge is not activated; and the cover is in the second position during a printhead priming.

10. A printing system comprising: a print cartridge to jet a fluid, wherein the print cartridge is movable between a print zone and a capping zone adjacent to the print zone; and a printhead capping system comprising: a cap comprising an elastomeric seal to enclose a printhead die on the print cartridge; a variable force capping station comprising: a cap plate to hold the cap and move in a first direction to interact with a launch shuttle tilt chute to lift the cap to a first position; and a launch shuttle to hold the cap plate and move in a second direction to interact with a base tilt chute to lift the cap to a second position; and a control system to move the cap plate and the launch shuttle in the first and second directions, respectively.

11. The printing system of claim 10, wherein the second direction is perpendicular to the first direction.

12. The printing system of claim 10, wherein the cap plate comprises a protrusion to interact with the print cartridge to slide the print cartridge in the second direction when the launch shuttle is moved in the second direction.

13. The printing system of claim 10, wherein the launch shuttle is translationally coupled to a base in the first direction.

14. The printing system of claim 10, wherein the cap plate is translationally coupled to the launch shuttle in the second direction.

15. The printing system of claim 10, further comprising a launch station; and wherein a pump of the launch station draws air through the printhead die of the print cartridge when the cap is in the second position.

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