An example printing fluid circulation system includes a first circuit to circulate a printing fluid through a printhead in a first direction and a second circuit to circulate the printing fluid through the printhead in a second direction opposite to the first direction. The first circuit is activated during a first mode to circulate the printing fluid from a first reservoir to a second reservoir. The second circuit is activated during a second mode different from the first mode to circulate the printing fluid from the first reservoir to the second reservoir.

Provided is an inkjet application device (1) including a distribution flow path for the liquid material, the distribution flow path including a first flow channel (4) configured to supply the liquid material pumped with a pump (2) to a supply tank (3) and a second flow channel (6) configured to supply the liquid material in the supply tank (3) to the inkjet head (5), wherein the supply tank (3) accommodates a filter (40), which is configured to allow the particles in the liquid material to pass therethrough without allowing air bubbles in the liquid material, which are generated by the pumping of the pump (2), to pass therethrough.

Provided is an inkjet application device (1) including a distribution flow path for the liquid material, the distribution flow path including a first flow channel (4) configured to supply the liquid material pumped with a pump (2) to a supply tank (3) and a second flow channel (6) configured to supply the liquid material in the supply tank (3) to the inkjet head (5), wherein the supply tank (3) accommodates a filter (40), which is configured to allow the particles in the liquid material to pass therethrough without allowing air bubbles in the liquid material, which are generated by the pumping of the pump (2), to pass therethrough.

A painting device equipped with a painting head having multiple nozzles that discharge coating material toward an object of painting. The painting device includes a supply passage that supplies the coating material to the painting head, and a return flow passage that returns, to the upstream side of the supply passage. A portion of the coating material supplied to the painting head that was not discharged from the multiple nozzles is possessed by the painting head, wherein the supply passage, the painting head, and the return flow passage constitute a coating material circulation passage. The coating material circulation passage is divided into multiple segments, each of which contains at least one of the multiple circuit component parts arranged in the coating material circulation passage or the painting head, and wherein the coating material circulation passage allows the multiple segments to be cleaned individually.

An inkjet head may include the following. A plurality of ink emitters, each including, an ink storage, a pressure changer which changes pressure in the ink stored in the ink storage, a nozzle which is connected to the ink storage and which emits ink according to a change in pressure in the ink in the ink storage, a plurality of precedent stage individual discharge flow paths which are connected to one ink storage and through which ink discharged without being supplied from the ink storage to the nozzle passes, and a subsequent stage individual discharge flow path to which, the plurality of precedent stage individual discharge flow paths join. A common discharge flow path may be connected to the plurality of subsequent stages individual discharge flow paths included in the plurality of ink emitters, and the ink which passes through the plurality of subsequent stage individual discharge flow paths flows.

According to examples, an apparatus may include a pump generator having a first resistance level and being positioned within a fluid circulation channel and a drop generator having a second resistance level and being positioned within a fluid ejection chamber. The apparatus may also include a control line connected to both the pump generator and the drop generator and a controller. The controller may output, at a first time, a first signal having a first pulse duration to the control line, the first signal to cause fluid in the fluid circulation channel to reach or exceed a first temperature and fluid in the fluid ejection chamber to remain below the first temperature and may output, at a second time, a second signal having a second pulse duration, the second signal to cause fluid in the fluid circulation channel and the fluid ejection chamber to reach or exceed the first temperature.

According to examples, an apparatus may include a pump generator having a first resistance level and being positioned within a fluid circulation channel and a drop generator having a second resistance level and being positioned within a fluid ejection chamber. The apparatus may also include a control line connected to both the pump generator and the drop generator and a controller. The controller may output, at a first time, a first signal having a first pulse duration to the control line, the first signal to cause fluid in the fluid circulation channel to reach or exceed a first temperature and fluid in the fluid ejection chamber to remain below the first temperature and may output, at a second time, a second signal having a second pulse duration, the second signal to cause fluid in the fluid circulation channel and the fluid ejection chamber to reach or exceed the first temperature.

In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

In one example, a conduit for returning liquid printing material to a liquid printing material storage tank in a printer comprises a first tubular section and a second section for receiving a flow of liquid printing material from the first tubular section. The second section is arranged to convert the flow of liquid material received from the first section into a falling liquid curtain of liquid printing material that is output from the second section to flow to the liquid printing material tank.