In an example, a fluid pump includes a shifter having a first end and pivotable about a second end, a cam rotatably engaged with the shifter, wherein the cam is to rotate about a cam shaft axis if the shifter pivots about the second end, a diaphragm fluidly engaged with a fluid cavity, a collar movable with a cam surface of the cam, wherein the collar is to compress the diaphragm so as to decrease the volume of the fluid cavity, a fluid inlet having a one-way inlet valve to only allow fluid into the fluid cavity, and a fluid outlet having a one-way outlet valve to only allow fluid out of the fluid cavity, wherein the one-way outlet valve is to allow fluid out of the fluid cavity upon the volume of the fluid cavity being decreased.

In an example, a fluid pump includes a shifter having a first end and pivotable about a second end, a cam rotatably engaged with the shifter, wherein the cam is to rotate about a cam shaft axis if the shifter pivots about the second end, a diaphragm fluidly engaged with a fluid cavity, a collar movable with a cam surface of the cam, wherein the collar is to compress the diaphragm so as to decrease the volume of the fluid cavity, a fluid inlet having a one-way inlet valve to only allow fluid into the fluid cavity, and a fluid outlet having a one-way outlet valve to only allow fluid out of the fluid cavity, wherein the one-way outlet valve is to allow fluid out of the fluid cavity upon the volume of the fluid cavity being decreased.

An ink reservoir for a printhead, an ink supply system and a printer are provided. The ink reservoir includes a main body including a first cavity, a second cavity, a first pipeline, a first inlet communicated with the first cavity, a first outlet communicated with the second cavity, a valve arranged in the first pipeline and a first film. The first cavity is communicated with the second cavity through the first pipeline. The first outlet is configured for mounting the printhead. The valve includes a piston and an elastic component configured to apply force to the piston in a direction from the first side toward the second side to allow a first end of the piston to block the first pipeline. The first film is provided at the second side for sealing the second cavity, and is abutted by a second end of the piston.

A liquid feeding device includes a diaphragm pump, a suction unit, and a discharge unit. The suction unit and the discharge unit are arranged in a stacking manner so that an inflow chamber of the suction unit and an outflow chamber of the discharge unit face the diaphragm on one side in a reciprocating direction of the diaphragm, and one of the suction unit and the discharge unit is attachable and detachable from the other.

A liquid feeding device includes a diaphragm pump, a suction unit, a discharge unit, and a filter unit. The filter unit includes a filter disposed between the suction unit and the discharge unit, so as to cover a liquid flow cross section. The suction unit and the discharge unit are arranged in a stacking manner so that the filter unit is sandwiched between them, and that an inflow chamber of the suction unit and an outflow chamber of the discharge unit face the diaphragm on one side in a reciprocating direction of the diaphragm.

A liquid discharge head includes a discharge element substrate configured to discharge a liquid, an upstream-side flow path connected to the discharge element substrate and configured to supply a liquid to the discharge element substrate, a downstream-side flow path connected to the discharge element substrate and configured to collect a liquid from the discharge element substrate, and a pump connected to each of the upstream-side flow path and the downstream-side flow path and configured to cause a liquid within the downstream-side flow path to flow out to the upstream-side flow path, wherein the pump includes a pump outflow hole for causing the liquid within the downstream-side flow path to flow out to the upstream-side flow path, and wherein, in a use state of the liquid discharge head, an opening of the pump outflow hole faces upward in a substantially vertical direction.

A droplet ejection apparatus includes: a plurality of tanks that store a liquid; a droplet ejection head that ejects droplets; a pump that sends out the liquid stored in an upstream tank on an upstream side in a liquid delivery direction to a downstream tank on a downstream side in the liquid delivery direction; a liquid channel that communicates the upstream tank and the downstream tank; a measurer that measures a value related to a liquid amount of the liquid in the downstream tank; and a hardware processor. The hardware processor determines whether there is an abnormality in the liquid channel. The hardware processor determines whether there is an abnormality in the liquid channel based on a change in a value related to the liquid amount in the downstream tank when the pump sends out the liquid for a predetermined liquid delivery time.