Abstract: A printing fluid pen includes a plurality of fluid ports, a pressure regulator in fluid communication with a first fluid port, and a valve in fluid communication with a second fluid port. The first fluid port is to deliver printing fluid to a fluid ejection device, and the second fluid port is to direct printing fluid out of the pen. In response to negative pressure, the valve is to open to enable fluids within the pen to exit via the second port.

Abstract: An example printing fluid pen comprises a plurality of fluid ports, a pressure regulator in fluid communication with a first fluid port, and a valve in fluid communication with a second fluid port. The first fluid port is to deliver printing fluid to a fluid ejection device, and the second fluid port to direct printing fluid out of the pen. In response to negative pressure, the valve is to open to enable fluids within the pen to exit via the second port.

Abstract: In one example, a shroud to protect a group of printheads in a printhead assembly includes a body having a first notched end where an upstream part of the body extends past a downstream part of the body and a second notched end opposite the first end where a downstream part of the body extends past an upstream part of the body. A first group of openings in the body is aligned across the upstream part of the body and a second group of openings in the body is aligned across the downstream part of the body. Each opening is to surround an exposed part of a printhead when the shroud is installed on the printhead assembly.

Abstract: Example implementations relate to liquid adsorption. In an example, a liquid adsorption system includes a vapor barrier container having a sealable internal volume, a liquid dispensing device in the internal volume, where the liquid dispensing device includes liquid in a liquid flow path extending through at least a portion of the liquid dispensing device to an opening in communication with the internal volume, and a liquid adsorbing material in the internal volume.

Abstract: In one example, a printhead assembly module includes an upstream row of printheads and a downstream row of printheads and a flow structure to distribute printing fluids to the printheads. The upstream and downstream rows of printheads are offset from one another such that a printhead in the upstream row extends past the downstream row at one end of the module and a printhead in the downstream row extends past the upstream row at the other end of the module. The flow structure includes a plate, slots in the plate to carry printing fluid to the printheads, and corresponding channels in the plate to distribute printing fluid to the slots. The slots and channels are arranged on the plate such that the arrangement is the same when rotated 180° about an axis of symmetry located at the geometric center of the arrangement.

Abstract: In some examples, a print bar includes a body, a plurality of printing fluid dispensing devices mounted to the body, and an assembly to carry a printing fluid to the printing fluid dispensing devices. The assembly comprises a first part having outlets to receive the printing fluid from a first conduit, and a second part attached to the first part, the second part having inlets aligned with the outlets of the first part, the second part to carry the printing fluid to the plurality of printing fluid dispensing devices. The assembly further comprises a pliable gasket comprising first and second flat sealing surfaces sealing the first and second parts around a first inlet of the inlets and a first outlet of the outlets, the first flat sealing surface contacting a ridge on one of the first and second parts, and the second flat sealing surface contacting a flat surface on the other of the first and second parts.

Abstract: Example implementations relate to liquid adsorption. In an example, a liquid adsorption system includes a vapor barrier container having a sealable internal volume, a liquid dispensing device in the internal volume, where the liquid dispensing device includes liquid in a liquid flow path extending through at least a portion of the liquid dispensing device to an opening in communication with the internal volume, and a liquid adsorbing material in the internal volume.

Abstract: In one example, a printhead assembly module includes an upstream row of printheads and a downstream row of printheads and a flow structure to distribute printing fluids to the printheads. The upstream and downstream rows of printheads are offset from one another such that a printhead in the upstream row extends past the downstream row at one end of the module and a printhead in the downstream row extends past the upstream row at the other end of the module. The flow structure includes a plate, slots in the plate to carry printing fluid to the printheads, and corresponding channels in the plate to distribute printing fluid to the slots. The slots and channels are arranged on the plate such that the arrangement is the same when rotated 180° about an axis of symmetry located at the geometric center of the arrangement.

Abstract: In one example, a shroud to protect a group of printheads in a printhead assembly includes a body having a first notched end where an upstream part of the body extends past a downstream part of the body and a second notched end opposite the first end where a downstream part of the body extends past an upstream part of the body. A first group of openings in the body is aligned across the upstream part of the body and a second group of openings in the body is aligned across the downstream part of the body. Each opening is to surround an exposed part of a printhead when the shroud is installed on the printhead assembly.

Abstract: In some examples, a print bar includes a body, a plurality of printing fluid dispensing devices mounted to the body, and an assembly to carry a printing fluid to the printing fluid dispensing devices. The assembly comprises a first part having outlets to receive the printing fluid from a first conduit, and a second part attached to the first part, the second part having inlets aligned with the outlets of the first part, the second part to carry the printing fluid to the plurality of printing fluid dispensing devices. The assembly further comprises a pliable gasket comprising first and second flat sealing surfaces sealing the first and second parts around a first inlet of the inlets and a first outlet of the outlets, the first flat sealing surface contacting a ridge on one of the first and second parts, and the second flat sealing surface contacting a flat surface on the other of the first and second parts.

Abstract: In one example, parts to be assembled into a fluid flow structure include: a first part having flat sealing surfaces each surrounding one of multiple first conduit openings; a second part having sealing ridges each surrounding one of multiple second conduit openings; and a single gasket having multiple holes each surrounded on both sides by a flat sealing surface. Each hole in the gasket is positioned to align with one of the first and second conduit openings so that, when the parts are assembled together, each gasket sealing surface contacts a corresponding one of the flat sealing surfaces on the first part or the sealing ridges on the second part and fluid may flow through the holes in the gasket from the conduit openings on one of the parts to the conduit openings on the other part.

Abstract: In one example, parts to be assembled into a fluid flow structure include: a first part having flat sealing surfaces each surrounding one of multiple first conduit openings; a second part having sealing ridges each surrounding one of multiple second conduit openings; and a single gasket having multiple holes each surrounded on both sides by a flat sealing surface. Each hole in the gasket is positioned to align with one of the first and second conduit openings so that, when the parts are assembled together, each gasket sealing surface contacts a corresponding one of the flat sealing surfaces on the first part or the sealing ridges on the second part and fluid may flow through the holes in the gasket from the conduit openings on one of the parts to the conduit openings on the other part.

Abstract: In one example, a printhead assembly datum includes stationary first and second points and a movable third point that define a datum plane for the printhead assembly. The stationary first and second points define a line in the datum plane and the third point is movable so that the datum plane pivots on the line in response to movement of the third point. In another example, a printhead assembly includes a body, a printhead attached to the body, and a datum for adjusting a position of the printhead relative to a component external to the printhead assembly. The datum is formed by first, second, and third datum points on the body that define a triangle representing a datum plane that is tiltable on the base of the triangle by moving the vertex opposite the base.

Abstract: In one example, a printhead assembly datum includes stationary first and second points and a movable third point that define a datum plane for the printhead assembly. The stationary first and second points define a line in the datum plane and the third point is movable so that the datum plane pivots on the line in response to movement of the third point. In another example, a printhead assembly includes a body, a printhead attached to the body, and a datum for adjusting a position of the printhead relative to a component external to the printhead assembly. The datum is formed by first, second, and third datum points on the body that define a triangle representing a datum plane that is tiltable on the base of the triangle by moving the vertex opposite the base.

Abstract: In one example, a print bar structure includes: a planar, rigid first part; an elongated second part having a front face on which one or more printheads may be mounted and a rear face opposite the front face; and an elongated third part having a front face. The second part and the third part are affixed to one another but not to the first part with the first part sandwiched tightly between the rear face of the second part and the front face of the third part such that the rear face of the second part and the front face of the third part conform to the planar shape of the first part.

Abstract: In one example, a print bar structure includes: a planar, rigid first part; an elongated second part having a front face on which one or more printheads may be mounted and a rear face opposite the front face; and an elongated third part having a front face. The second part and the third part are affixed to one another but not to the first part with the first part sandwiched tightly between the rear face of the second part and the front face of the third part such that the rear face of the second part and the front face of the third part conform to the planar shape of the first part.

Abstract: A manifold assembly for a fluid-ejection device having multiple-fluid type fluid-ejection printheads organized in a page-wide array includes a lower-most deck and an upper-most deck. The lower-most deck is to supply a first type of fluid and a second type of fluid to the fluid-ejection printheads. The first type of fluid and the second type of fluid are exterior-most fluids ejected by the fluid-ejection printheads in relation to a direction of media movement through the fluid-ejection device. The upper-most deck is to supply a third type of fluid and a fourth type of fluid to the fluid-ejection printheads. The third type of fluid and the fourth type of fluid are interior-most fluids ejected by the fluid-ejection printheads in relation to the direction of media movement through the fluid ejection device.

Abstract: In one embodiment, a fluid ejector assembly includes: a bay for holding a detachable fluid container that includes a fluid outlet at a forward part of the container; a fluid ejector; a fluid inlet at a forward part of the bay through which fluid from the outlet of a fluid container installed in the bay may pass to the fluid ejector; and a stationary guide configured to block an improper installation of a fluid container into the bay without also blocking a proper installation of the fluid container into the bay.

Abstract: A manifold assembly for a fluid-ejection device having multiple-fluid type fluid-ejection printheads organized in a page-wide array includes a lower-most deck and an upper-most deck. The lower-most deck is to supply a first type of fluid and a second type of fluid to the fluid-ejection printheads. The first type of fluid and the second type of fluid are exterior-most fluids ejected by the fluid-ejection printheads in relation to a direction of media movement through the fluid-ejection device. The upper-most deck is to supply a third type of fluid and a fourth type of fluid to the fluid-ejection printheads. The third type of fluid and the fourth type of fluid are interior-most fluids ejected by the fluid-ejection printheads in relation to the direction of media movement through the fluid ejection device.

Abstract: In one embodiment, a fluid ejector assembly includes: a bay for holding a detachable fluid container that includes a fluid outlet at a forward part of the container; a fluid ejector; a fluid inlet at a forward part of the bay through which fluid from the outlet of a fluid container installed in the bay may pass to the fluid ejector; and a stationary guide configured to block an improper installation of a fluid container into the bay without also blocking a proper installation of the fluid container into the bay.