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.

Fluid printing apparatus including substrate, print head, pneumatic system, and print head positioning system. The print head ejects fluid in a continuous stream with a micro-structural fluid ejector consisting of output, elongate input, and tapering portions between the output and elongate input portions. The output portion consists of an exit orifice of an inner diameter ranging between 0.1 μm and 5 μm and an end face having a surface roughness of less than 0.1 μm. The print head is positioned above the substrate with the output portion of the micro-structural fluid ejector pointing downward. During printing, the print head positioning system maintains a vertical distance between the end face and the printable surface of the substrate within a range of 0 μm to 5 μm, and the pneumatic system applies pressure to the fluid in the micro-structural fluid ejector in the range of −50,000 Pa to 1,000,000 Pa.

Method of printing fluid on a printable surface of a substrate. A print head ejects fluid in a continuous stream. The print head that includes a micro-structural fluid ejector, which consists of output, elongate input, and tapering portions between the output and the elongate input portions. The output consists of an exit orifice of an inner diameter ranging between 0.1 μm and 5 μm and an end face having a surface roughness of less than 0.1 μm. The print head is positioned above the substrate with the output of the micro-structural fluid ejector pointing downward. During printing, the print head positioning system maintains a vertical distance between the end face and the printable surface of the substrate within a range of 0 μm to 5 μm, and the pneumatic system applies pressure to the fluid in the micro-structural fluid ejector in the range of −50,000 Pa to 1,000,000 Pa.

A liquid supply device includes a first conduit, a second conduit, one or more pumps, a heater, a filter, and a bypass conduit. The first conduit is connected to an upstream side of a liquid discharge head. The second conduit is connected to a downstream side of the liquid discharge head. The liquid is supplied through the first conduit to the liquid discharge head and recovered from the liquid discharge head through the second conduit. The heater is provided along the first conduit. The filter is provided in the first conduit on a downstream side of the heater. The bypass conduit is connected between a portion of the first conduit upstream with respect to the filter and a portion of the second conduit.

A liquid discharger includes a head including nozzles to discharge liquid from the nozzles, a detachable first container attached to the liquid discharger to accommodate the liquid, a second container connected to the head to accommodate the liquid to be supplied to the head, a supply channel to connect the first container and the second container, an irreversible pump connected to the second container, and a controller to control the irreversible pump to pressurize and decompress the second container to reciprocally move the liquid between the first detachable container and the second container via the supply channel.

A printing apparatus includes an ink tank and a flow channel member. The tank includes an ink chamber that stores ink, an injection port through which the ink is injected into the chamber, and a first shape portion formed near the injection port. The flow channel member is configured to be disposed inside the injection port and form a channel through which the ink is injected into the chamber. The ink is injected to the chamber from an ink supply container which includes a second shape portion formed near an outlet port of the container and configured to engage the first shape portion. The flow channel member is displaceable in a direction intersecting an inserting direction of inserting the outlet port into the injection port. The container is fixed to the tank by engagement between the first and second shape portions.

A valve for connecting a second-flow-channel, which supplies a liquid to a liquid-ejecting-head, with a first-flow-channel of the liquid-ejecting-head which ejects the liquid, includes a valve-casing, a first-connector that detachably connects the first-flow-channel, a second-connector that connects the second-flow-channel, a first-connection-port that communicates with the first-flow-channel which is connected with the first-connector, a second-connector that communicates with the second-flow-channel which is connected with the second-connector, and a valve-body in which a connecting-flow-channel is formed for connecting the first-connection-port and the second-connection-port, and that is moved inside the valve-casing to switch a connection state between the first-connection-port and the second-connection-port among a plurality of states. The plurality of states include a first state in which the first-connection-port and the second-connection-port communicate with each other via the connecting-flow-channel, and a second state in which the first-connection-port and the second-connection-port are disconnected.

A liquid ejecting apparatus has a liquid ejecting unit and a negative pressure regulating unit provided between passages connecting the tank to the liquid ejecting unit, regulates fluid pressure of liquid flowing into the liquid ejecting unit. The negative pressure regulating unit includes a negative pressure chamber whose internal pressure is regulated within a predetermined range, and a discharging passage for discharging liquid stored in the negative pressure chamber from the negative pressure regulating unit. The discharging passage has an outlet disposed in an upper portion of the negative pressure chamber in a direction of gravity, a bubble accumulation portion connected to the outlet and having a space above the outlet in the direction of gravity, and a passage guiding liquid flowing from the outlet to a discharging port opened in a bottom of the negative pressure regulating unit.

An object is to provide a liquid ejection apparatus that allows suppression of a fluctuation in a pressure of a liquid in a flow path caused by a liquid delivery unit, enabling the liquid to be stably ejected through an ejection port. The liquid ejection apparatus including a liquid ejection head having an ejection port through which a liquid is ejected, a flow path configured to communicate with the ejection port, and a liquid delivery unit configured to feed the liquid to the flow path. A relation between an angular frequency ω of the liquid delivered from the liquid delivery unit, a coefficient of kinematic viscosity ν of the liquid, and an equal diameter a of at least a part of a section of an extra-head flow path in a direction normal to a direction in which ink flows satisfies √(ω/2ν)×a>1.

A liquid management system for supplying or receiving liquid at a controlled pressure, comprising: a closed reservoir having an inlet for receiving liquid from a first remote location and an outlet for supplying liquid to a second remote location; and a pumped outlet disposed in the reservoir and arranged to remove liquid and gas contained within the reservoir, the pumped outlet being disposed such that the level of liquid in the reservoir can be maintained at a constant height.