An apparatus for supplying chemical liquid may include at least two ink jet heads, a reservoir for receiving a chemical liquid provided onto a substrate from each of the at least two ink jet heads, a chemical liquid for supplying member providing the chemical liquid to each of the at least two ink jet heads, and a chemical liquid collecting member for drawing and collecting a chemical liquid remained in each of the at least two ink jet heads. One path of the chemical liquid from the chemical liquid supplying member to the chemical liquid collecting member via one of the at least two ink jet heads may be substantially the same as a length of another path the of chemical liquid from the chemical liquid supplying member to the chemical liquid collecting member via the other of the at least two ink jet heads.

An example printing material cartridge includes a reservoir storing printing material to supply a printing apparatus and a storage medium storing process instructions for controlling the recirculation process in the printing apparatus.

A liquid discharge apparatus comprises a head including a discharge port surface, a first reservoir that stores the liquid to be supplied to the head, a flexible member, separating an inner space of the first reservoir into a first chamber that stores the liquid and a second chamber that stores an operation liquid, a second reservoir communicating with the second chamber, the second reservoir storing the operation liquid to be supplied to the second chamber, the second reservoir being disposed in such a manner that a liquid surface of the operation liquid stored in the second reservoir is positioned below the discharge port surface, and an adjustment unit that performs adjustment in such a manner that a position of the liquid surface of the operation liquid in the second reservoir falls within a predetermined range in a state where the second reservoir is opened to atmosphere.

A liquid discharge apparatus comprises a head including a discharge port surface, a first reservoir that stores the liquid to be supplied to the head, a flexible member, separating an inner space of the first reservoir into a first chamber that stores the liquid and a second chamber that stores an operation liquid, a second reservoir communicating with the second chamber, the second reservoir storing the operation liquid to be supplied to the second chamber, the second reservoir being disposed in such a manner that a liquid surface of the operation liquid stored in the second reservoir is positioned below the discharge port surface, and an adjustment unit that performs adjustment in such a manner that a position of the liquid surface of the operation liquid in the second reservoir falls within a predetermined range in a state where the second reservoir is opened to atmosphere.

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.

Disclosed herein is a fluid supply system that can provide fluid to a jetting assembly at a constant pressure or at pressures within a desired range of pressures. In an example, the fluid can be ink, and the jetting assembly can be a print head configured for dispensing the ink.

Provided are an inkjet printing apparatus and a recovery method capable of suppressing ink thickening in the ejection openings in the suction process for the ejection openings. A vacuum wiper is moved being in contact with the ejection opening surface of the print head to perform a vacuum wiping process for the arrayed ejection openings sequentially. Ink is circulated in flow paths including the flow paths communicating with the ejection openings for which the vacuum wiping process has been finished.

An inkjet printing apparatus is provided with a tank that stores ink, a print head that performs print operation by ejecting ink supplied from the tank, a circulation unit that establishes a circulating state to circulate ink in a circulation path if print operation is performed and establishes a stopped state to stop circulation of ink if print operation is terminated, and a deaeration unit that performs deaeration operation to deaerate ink inside the circulation path. The apparatus includes an estimation unit that estimates a dissolved gas amount in ink inside the circulation path based on dissolved gas amounts increased in the circulating state and in the stopped state, respectively, and a control unit that causes the deaeration unit to execute deaeration operation after completion of print operation if the dissolved gas amount estimated by the estimation unit exceeds a predetermined threshold.

In one example, a dehumidifier for an inkjet printer includes a condensing unit and a chiller to circulate coolant through the condensing unit. The condensing unit is made of a thermally conductive material forming elongated exterior condensing surfaces and an interior coolant flow passage extending lengthwise between the condensing surfaces.