A discharger is configured to discharge liquid in a liquid channel to outside the liquid channel The liquid is at least one of first liquid and second liquid different from the first liquid. An agitator is configured to agitate the liquid in the liquid channel When executed by a processor, instructions cause the processor to perform: an introducing process of, when the second liquid exists in the liquid channel, controlling the discharger to discharge the second liquid to outside the liquid channel and to introduce the first liquid from the tank into the liquid channel; an agitating process of, after the introducing process, controlling the agitator to agitate the liquid in the liquid channel; and a discharging process of, after the agitating process, controlling the discharger to discharge the liquid in the liquid channel agitated by the agitator to outside the liquid channel

A discharger is configured to discharge liquid in a liquid channel to outside the liquid channel The liquid is at least one of first liquid and second liquid different from the first liquid. An agitator is configured to agitate the liquid in the liquid channel When executed by a processor, instructions cause the processor to perform: an introducing process of, when the second liquid exists in the liquid channel, controlling the discharger to discharge the second liquid to outside the liquid channel and to introduce the first liquid from the tank into the liquid channel; an agitating process of, after the introducing process, controlling the agitator to agitate the liquid in the liquid channel; and a discharging process of, after the agitating process, controlling the discharger to discharge the liquid in the liquid channel agitated by the agitator to outside the liquid channel

An inkjet printing apparatus and its control method which can suppress defective ejection and wasteful ink consumption are provided. For that purpose, pigment density N.sub.x of the ink in a circulation path is calculated, and the ink in the circulation path is discharged on the basis of the pigment density N.sub.x.

Provided are a valve unit, a printing apparatus, and a printing method capable of preventing sediment arising in the valve unit from flowing toward a discharge unit.

The valve unit is used in a printing apparatus including a reservoir unit that holds ink, a discharge unit configured to discharge the ink, and a flow channel that connects the reservoir unit to the discharge unit and through which the ink flows from the reservoir unit to the discharge unit. The valve unit is disposed partway along the flow channel, and includes: a first chamber that configured to communicate with the reservoir unit; a second chamber configured to communicate with the discharge unit; a switching valve that switches between allowing and cutting off a flow of ink from the first chamber to the second chamber; and an expelling unit configured to expel sediment from the second chamber by suctioning the sediment.

Provided are a valve unit, a printing apparatus, and a printing method capable of preventing sediment arising in the valve unit from flowing toward a discharge unit.

The valve unit is used in a printing apparatus including a reservoir unit that holds ink, a discharge unit configured to discharge the ink, and a flow channel that connects the reservoir unit to the discharge unit and through which the ink flows from the reservoir unit to the discharge unit. The valve unit is disposed partway along the flow channel, and includes: a first chamber that configured to communicate with the reservoir unit; a second chamber configured to communicate with the discharge unit; a switching valve that switches between allowing and cutting off a flow of ink from the first chamber to the second chamber; and an expelling unit configured to expel sediment from the second chamber by suctioning the sediment.

A pump for the transfer a predetermined total volume of fluid from a pump inlet to a pump outlet in a unit of time is calibrated by deriving a count of the number of times a volume of the fluid is transferred from a pump inlet to a pump outlet in a unit of time; and adjusting the number of times the volume is transferred in a unit of time until the derived count is substantially equal to a predetermined threshold value.

A jetting device includes an ejection unit arranged to eject a droplet of a liquid. The ejection unit includes a nozzle, a liquid duct connected to the nozzle, and an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct. The jetting device further includes a filter arranged to filter the liquid being supplied into the duct and a filter status detection system arranged to detect an obstruction status of the filter by measuring a property of the liquid in the duct. The filter status detection system includes a circuit configured for measuring the electric response of the transducer, for recording changes in the electric response that represent pressure fluctuations induced by the acoustic wave in the form of a time-dependent function, and for judging the obstruction status of the filter on the basis of that function.

An ink composition includes water, a co-solvent, a colorant, and a modified polymer or copolymer additive. The modified polymer or copolymer additive is selected from the group consisting of i) a hydrolyzed poly(isobutylene-alt-maleic anhydride), ii) a hydrolyzed poly(maleic anhydride-alt-1-octadecene), and iii) a modified polymer or copolymer. The modified polymer or copolymer includes a repeating unit of a backbone chain, and a long chain pendant group attached to a carbon atom of the repeating unit. In the backbone chain, the long chain pendant group of the repeating unit is separated by fewer than 8 spacer carbon atoms from another long chain pendant group of an adjacent repeating unit.

A printing-fluid containing device configured to be inserted into a cartridge attachment section in an insertion direction includes: a printing-fluid cartridge and an adaptor to which the cartridge is detachably assembled. The cartridge includes: a casing; a supply portion; a detection portion; and an engagement portion. The adaptor includes: an adaptor body; and an electrical interface. The detection portion includes a light accessible portion accessed by light from an outside of the cartridge. The engagement portion is engageable with the cartridge attachment section. The adaptor body has a front wall at its leading end in the insertion direction. The front wall has an opening through which the supply portion extends. The electrical interface is disposed on an outer surface of the adaptor body and electrically connectable to an electric contact of the cartridge attachment section.

An inkjet printing apparatus includes a surface acoustic wave module including an inner passage and a surface acoustic wave generator around the inner passage; and an outflow passage connected to the surface acoustic wave module to discharge ink, where the outflow passage includes a first outflow passage connected to the inner passage to discharge first ink particles and a second outflow passage connected to the inner passage to discharge second ink particles having an average diameter smaller than that of the first ink particles, and the surface acoustic wave generator is closer to the second outflow passage than the first outflow passage.