The image formation device includes a tank, a hollow member, and a sensor. The tank is configured to store ink. The hollow member is disposed inside the tank, and extends in an up-down direction. The sensor is disposed outside the tank and above the hollow member, and is configured to detect a pressure inside the hollow member.

A fluid reservoir (100) includes a circuit (105) extending in the fluid reservoir to be at least partially in contact with fluid (120) inside the fluid reservoir during use, at least a first impedance sensor (110) and second impedance sensor (115) coupled to the circuit, wherein the at least first and second impedance sensors are to output impedance values indicative of a degree of particle separation in the fluid.

A fluid reservoir (100) includes a circuit (105) extending in the fluid reservoir to be at least partially in contact with fluid (120) inside the fluid reservoir during use, at least a first impedance sensor (110) and second impedance sensor (115) coupled to the circuit, wherein the at least first and second impedance sensors are to output impedance values indicative of a degree of particle separation in the fluid.

A liquid discharge apparatus is provided that includes a transport unit configured to transport a medium, a discharge unit configured to discharge a liquid onto the medium, a housing including therein the discharge unit, a humidifying unit configured to humidify an interior of the housing, and a humidity detection unit configured to detect a humidity. When the humidity detection unit detected a humidity less than a lower limit value (one example of a first predetermined value) (positive determination in step S12), the interior of the housing is humidified by the humidifying unit during transport by the transport unit or during discharge by the discharge unit (step S16).

A logic circuitry package for a replaceable print apparatus component comprises an interface to communicate with a print apparatus logic circuit, and at least one logic circuit. The logic circuit may be configured to identify, from a command stream received from the print apparatus, parameters including a class parameter, and/or identify, from the command stream, a read request, and output, via the interface, a count value in response to a read request, the count value based on identified received parameters.

A fluid ejection device includes a fluid slot, at least one fluid ejection chamber communicated with the fluid slot, a drop ejecting element within the at least one fluid ejection chamber, a fluid circulation channel communicated with the fluid slot and the at least one fluid ejection chamber, and a fluid circulating element communicated with the fluid circulation channel. The fluid circulating element is to provide on-demand circulation of fluid from the fluid slot through the fluid circulation channel and the at least one fluid ejection chamber.

An image forming apparatus includes: an ink-jet head including a storage that stores phase transition ink, the ink jet head forms an image on a recording medium by ejecting the phase transition ink; and one or more hardware processors. The one or more hardware processors change a driving condition of the ink jet head for a case of ejecting the phase transition ink on a basis of a first reading result of a pattern image formed by the ink-jet head; estimate occurrence of a state change of the phase transition ink in the storage when the driving condition that is changed satisfies a predetermined condition; and determine whether a lifetime of the ink jet head is over in accordance with whether the occurrence of the state change is estimated.

An image forming apparatus includes: an ink-jet head including a storage that stores phase transition ink, the ink jet head forms an image on a recording medium by ejecting the phase transition ink; and one or more hardware processors. The one or more hardware processors change a driving condition of the ink jet head for a case of ejecting the phase transition ink on a basis of a first reading result of a pattern image formed by the ink-jet head; estimate occurrence of a state change of the phase transition ink in the storage when the driving condition that is changed satisfies a predetermined condition; and determine whether a lifetime of the ink jet head is over in accordance with whether the occurrence of the state change is estimated.

An ink heating device that is disposed on an inkjet recording device and heats ink includes an ink tank and at least one heater to heat the ink tank. The ink tank is an integrated unit of subtanks storing ink disposed along the longitudinal direction. The at least one heater heats both longitudinal ends of the ink tank to a temperature higher than a temperature of a central area in the longitudinal direction of the ink tank.

An inkjet recording apparatus for curing ink ejected onto a base material and forming recorded matter on the base material is provided. The inkjet recording apparatus includes an ejection unit configured to eject the ink onto a first area of the base material and a second area surrounded by the first area, a curing unit configured to cure the ink ejected onto the base material, and a control unit configured to control the curing unit in such a way that a time from ink ejection onto the first area to ink curing is longer than a time from ink ejection onto the second area to ink curing.