An inkjet printing device includes a stage; an inkjet head disposed above the stage and comprising nozzles through which ink is discharged, the ink including bipolar elements extending in a direction; an ink circulation part which supplies the ink to the inkjet head, and to which the ink remaining after being discharged from the inkjet head is supplied; and at least one sensing part disposed between the inkjet head and the ink circulation part and sensing a number of the bipolar elements that are discharged through the nozzles.

An inkjet printing device includes a stage; an inkjet head disposed above the stage and comprising nozzles through which ink is discharged, the ink including bipolar elements extending in a direction; an ink circulation part which supplies the ink to the inkjet head, and to which the ink remaining after being discharged from the inkjet head is supplied; and at least one sensing part disposed between the inkjet head and the ink circulation part and sensing a number of the bipolar elements that are discharged through the nozzles.

A backside channel is fluidically connected between a supply inlet and a backside outlet. The backside channel has a backside channel fluid recirculation path. An element channel is fluidically connected to an element outlet. Fluid-ejection elements are fluidically connected between the backside channel and the element channel. The fluid-ejection elements have a fluid-ejection element fluid recirculation path.

A backside channel is fluidically connected between a supply inlet and a backside outlet. The backside channel has a backside channel fluid recirculation path. An element channel is fluidically connected to an element outlet. Fluid-ejection elements are fluidically connected between the backside channel and the element channel. The fluid-ejection elements have a fluid-ejection element fluid recirculation path.

According to an aspect of the present invention, an inkjet printing apparatus includes a print head having an ejection opening surface on which ejection openings for ejecting ink are formed, a tank storing ink to be supplied to the print head, a supply flow path for supplying the ink from the tank to the print head, a collection flow path for collecting the ink from the print head to the tank, a supply pump provided in the supply flow path to supply the ink from the tank to the print head, a tank decompression pump which decompresses the inside of the tank, and a control unit which controls to drive the supply pump and the tank decompression pump to fill the collection flow path with ink.

According to an aspect of the present invention, an inkjet printing apparatus includes a print head having an ejection opening surface on which ejection openings for ejecting ink are formed, a tank storing ink to be supplied to the print head, a supply flow path for supplying the ink from the tank to the print head, a collection flow path for collecting the ink from the print head to the tank, a supply pump provided in the supply flow path to supply the ink from the tank to the print head, a tank decompression pump which decompresses the inside of the tank, and a control unit which controls to drive the supply pump and the tank decompression pump to fill the collection flow path with ink.

A liquid discharge apparatus includes a plurality of heads configured to discharge a liquid, a supply channel connected to the plurality of heads, the supply channel configured to supply the liquid to the plurality of heads, a collection channel connected to the plurality of heads, the collection channel configured to collect the liquid from the plurality of heads, a supply damper configured to define a deformable wall of the supply channel, a collection damper configured to define a deformable wall of the collection channel, a supply damper chamber facing the supply damper, a collection damper chamber facing the collection damper, a pressure pump configured to apply a pressure to the supply damper chamber, and a depressurize pump configured to apply a negative pressure to the collection damper chamber.

An inkjet recording device including: inkjet head having a pressure chamber; a first pressure source to adjust ink energy per unit volume to generate “energy per unit volume” P1(Pa) relative to static ink at an atmospheric pressure at a nozzle opening height; a second pressure source to adjust ink energy per unit volume to generate “energy per unit volume” P2(Pa) relative to static ink; and a hardware processor. The first pressure source, pressure chamber, and second pressure source are connected in this order by a flow path. Assuming that a pressure loss occurring from the first pressure source to the nozzle due to circulation flow rate is ΔPa, a proportionality constant of a differential pressure (P1−P2) and ΔPa is “a”, and an appropriate pressure in vicinity of the nozzle opening is Pn, the hardware processor controls pressure to establish P2={Pn−(1−a)P1}/a.

a first sloped portion that is provided between the first wall surface and the third wall surface includes a first constituting surface that extends in a third direction between the first direction and the second direction.

a first sloped portion that is provided between the first wall surface and the third wall surface includes a first constituting surface that extends in a third direction between the first direction and the second direction.