A liquid supply member includes a first member, a second member, and a damper member disposed between the first member and the second member, wherein the first member is a member configured to form a liquid chamber, wherein the damper member is a flexible member configured to form the liquid chamber together with the first member, wherein the second member is a member configured to form an atmosphere communication chamber communicating with an ambient atmosphere at a position between the damper member and the second member and opposing the liquid chamber with the damper member in between, and wherein a protrusion portion is formed on a surface of the second member facing the atmosphere communication chamber at a position corresponding to a central part of the damper member, the protrusion portion protruding toward the damper member beyond a connection surface between the damper member and the second member.

A liquid circulation mechanism includes a supply flow path making a liquid supply source and a liquid discharging head communicate with each other and a collection flow path making the liquid discharging head and a connection portion of the supply flow path communicate with each other, in which a branch portion, a plurality of flow paths branched at the branch portion, and a merging portion, in which the plurality of flow paths are merged, are provided in at least one of the supply flow path and the collection flow path. Pressure adjustment portions, which are provided in the plurality of flow paths and open the flow paths when a pressure on the liquid discharging head side is equal to a predetermined pressure, have different the predetermined pressures for opening the flow paths in the plurality of flow paths.

A logic circuitry package for a replaceable print apparatus component includes an interface to communicate with a print apparatus logic circuit, and at least one logic circuit to receive, via the interface, requests corresponding to different sensor IDs with the component connected to the apparatus. The logic circuit is to transmit, via the interface, a digital value in response to each request. The digital values corresponding to the different sensor IDs are distinct.

A replenishing-type liquid storage tank includes a tank body, and a backpressure application member. Liquid is replenishable in the tank body and the tank body is configured to store the liquid therein. The backpressure application member is accommodated in the tank body to apply backpressure to the liquid stored in the tank body. The backpressure application member has a lower end positioned at a height equal to or lower than a liquid level of a minimum amount of liquid required to be stored in the tank body for enabling the backpressure application member to apply backpressure to the liquid stored in the tank body.

In one example in accordance with the present disclosure, a method of determining a printing fluid level is described. According to the method, an on-time of a pump is determined. The pump maintains a fixed pressure in a pressurized reservoir. From the on-time, a fluid level in the pressurized reservoir is determined.

A printer comprising a printhead configured to selectively cause a mark to be created on a substrate. The printer comprises a stepper motor having an output shaft coupled to the printhead, the stepper motor being arranged to vary the position of the printhead relative to a printing surface against which printing is carried out, and to control the pressure exerted by the printhead on the printing surface. The printer further comprises a sensor configured to generate a signal indicative of an angular position of the output shaft of the stepper motor. The printer further comprises a controller arranged to generate control signals for the stepper motor so as to cause a predetermined torque to be generated by the stepper motor; said control signals being at least partially based upon an output of said sensor.

An ink recirculation system for recirculating printheads includes a housing with two chambers, a series of pressure sensors, a vacuum generator and a pressure generator The container has two entrances for transmitting signals towards the pressure sensors, a first feed connection to the printhead, a second flow connection to the printhead, a third ink feed connection, a fourth connection for returning the ink to the main tank and means for connecting and supporting the vacuum generator and the pressure generator.

There is disclosed a fluid container 200 useable with print apparatus. The fluid container comprises a primary module 210 comprising: a primary reservoir 220 to contain print fluid and a regulated chamber 230 to receive the print fluid from the primary reservoir 220. The regulated chamber 203 comprises a regulator unit 232 to actuate a gas control valve 234 to control a flow of relief gas into the fluid container 200 as print fluid is discharged from the fluid container 200. The fluid container comprises a secondary module 250 comprising a secondary reservoir 252 to contain print fluid. The primary reservoir 220 is to receive the print fluid from the secondary reservoir 252 via a re-supply conduit 260 between the secondary reservoir 252 and the primary reservoir 220. The secondary reservoir 252 is to receive the relief gas via the gas control valve 234, and the primary reservoir 220 is to receive the relief gas via the secondary reservoir 252.

In some examples, an apparatus includes a pressure sensor, and a controller to determine, based on pressure data from the pressure sensor, an amount of time to depressurize a fluid supply from a first pressure to a second pressure, and determine a level of a fluid in the fluid supply based on the amount of time to depressurize the fluid supply from the first pressure to the second pressure.

In some examples, an apparatus can include a valve body including a valve body print substance channel and a valve body air channel, a valve socket shaped to receive the valve body, where the valve socket includes a valve socket print substance channel and a valve socket air channel, where the valve body is in a closed position such that the valve body print substance channel and the valve socket print substance channel are misaligned, and the valve body air channel and the valve socket air channel are misaligned.