A head module includes a pressure chamber, a piezoelectric member, a supply manifold, a return manifold, and a damper portion. The pressure chamber is configured to hold liquid therein and in fluid communication with a nozzle orifice. The piezoelectric member is configured to apply pressure to liquid held in the pressure chamber. The supply manifold is in fluid communication with the pressure chamber and configured to allow liquid to flow into the pressure chamber therefrom. The return manifold is in fluid communication with the pressure chamber and configured to allow liquid not ejected from the nozzle orifice to flow thereinto. The damper portion is positioned between the supply manifold and the return manifold when viewed in plan from a nozzle surface of the head module. The nozzle surface has the nozzle orifice defined therein. The damper portion includes a particular plate having a particular recessed portion.

A physical quantity detection device including a container that accommodates a detection object formed of a dielectric, a first electrode provided at an outer side of the container, a second electrode that is provided separately from and to face the first electrode, and an electrostatic capacitance detector that detects an electrostatic capacitance between the first electrode and the second electrode. The electrostatic capacitance detector includes a waveform generation source coupled to the first electrode and a voltage detection circuit coupled to the second electrode. A relationship of |Zc|/|Z1|+|Zc|>|Zc|/|Z2|+|Zc| is satisfied in which |Zc| is an absolute value of an input impedance of the electrostatic capacitance detector, |Z1| is an absolute value of an impedance when the detection object is present between the first electrode and the second electrode, and |Z2| is an absolute value of an impedance when no detection object is present between the first electrode and the second electrode.

An information processing device includes a storage portion storing a learned model, a reception portion receiving air pressure information and temperature information at a time of ejecting ink, and a processing portion controlling a pressurization pump based on the received air pressure information and temperature information and the learned model. The learned model is a learned model trained by performing machine learning of a condition of a pressurization force with which a determination that an ejection failure does not occur is made, based on a data set in which the air pressure information in a usage environment of a printing apparatus including a printing head, the temperature information in the usage environment, and pressurization force information about the pressurization pump supplying the ink to the printing head are associated.

A liquid surface detector includes an electrode pad, a coil, a memory, and a detection control circuit. The electrode pad is attached to an outer side surface of a tank of the image forming apparatus. The coil is connected to the electrode pad. The memory stores initial values. The detection control circuit determines a capacitance (first capacitance) of a first resonance circuit including the coil and the tank with the electrode pad. When determining a liquid surface level value, the detection control circuit subtracts an error value from the first capacitance so as to determine a first corrected capacitance, and determines the liquid surface level value based on the first corrected capacitance and the initial value.

An example input voltage agnostic fluidic device may include a level shifter to adjust an input voltage of control signals received at an input interconnect to a voltage level that is within operational thresholds of on-chip devices of the input voltage agnostic fluidic device.

An example recirculation fluid ejection device includes a first unit droplet generator including a first actuator and a first nozzle between a first and a second fluid feed hole, the first fluid feed hole located on a first channel and the second fluid feed hole and a first pump located on a second channel. The example device includes a second unit droplet generator including a second actuator and a second nozzle between a third and a fourth fluid feed hole, the third feed hole located on a third channel and the fourth fluid feed hole and a second pump located on a fourth channel. The first and the second actuators eject fluid at substantially the same backpressure. A first pressure measurable at an inlet of the first channel and the third channel are different from a second pressure measurable at an outlet of the second channel and the fourth channel.

A liquid ejecting device includes a flow path member, an actuator, a pump, and a controller. The flow path member includes a flow path configured to direct flow of a pseudoplastic liquid through the flow path member. The actuator is configured to cause droplets to be ejected. The pump is configured to cause the liquid to flow sequentially through a supply reservoir, a plurality of supply manifolds, a plurality of supply flow paths, and a plurality of pressure chambers. The controller is configured to adjust a flow rate of the liquid to a prescribed target flow rate. The flow path has a flow path shape in which an average viscosity of the liquid in the plurality of supply flow paths is less than or equal to half an average viscosity of the liquid in the plurality of supply manifolds when the flow rate is equal to the target flow rate.

An ink supply tube includes: a first layer that is made of an unmodified ethylene-tetrafluoroethylene copolymer resin and is in contact with ink; a second layer that is made of a modified ethylene-tetrafluoroethylene copolymer resin and is formed on an outer periphery of the first layer; a third layer that is made of a polyamide resin or a basic functional group-modified polypropylene resin and is formed on an outer periphery of the second layer; a fourth layer that is made of an ethylene-vinyl alcohol copolymer resin having a gas barrier property and is formed on an outer periphery of the third layer; and a fifth layer that is made of an acid functional group-modified polypropylene resin and is formed on an outer periphery of the fourth layer.

An ink supply tube includes: a first layer that is made of an unmodified ethylene-tetrafluoroethylene copolymer resin and is in contact with ink; a second layer that is made of a modified ethylene-tetrafluoroethylene copolymer resin and is formed on an outer periphery of the first layer; a third layer that is made of a polyamide resin or a basic functional group-modified polypropylene resin and is formed on an outer periphery of the second layer; a fourth layer that is made of an ethylene-vinyl alcohol copolymer resin having a gas barrier property and is formed on an outer periphery of the third layer; and a fifth layer that is made of an acid functional group-modified polypropylene resin and is formed on an outer periphery of the fourth layer.

[Object] To appropriately warm ink.

[Solving Means] An inkjet printer 1 includes an inkjet head 3 and an ink warming mechanism 12. The ink warming mechanism 12 includes a warming part main body 21; an ink flow path 21a formed inside the warming part main body 21; a heater 22 that is attached to the warming part main body 21 and heats the warming part main body 21; a warming part temperature sensor 23 that is attached to the warming part main body 21 and detects a temperature of the warming part main body 21; and a heater controller 4 that controls the heater 22. The heater controller 24 controls the heater 22 based on the detection result of the warming part temperature sensor 23 so that the temperature of the warming part main body 21 becomes a predetermined reference temperature.