Aspects of a disclosure relates to a liquid discharge device enables previously disabled liquid discharge through a head after a cartridge including a first liquid chamber is replaced and before the liquid level in a second liquid chamber of a tank reaches a predetermined level or higher. Another aspects of the disclosure relates to a liquid discharge device that deactivates an alarm after a cartridge including a first liquid chamber is replaced and before the liquid level in a second liquid reaches a predetermined level or higher.

A printing device to which a predetermined flat-rate usage fee is applied regardless of the number of times a cartridge is replaced includes an ejection head having a nozzle capable of ejecting a liquid stored in each of a plurality of cartridges, and a controller, wherein the controller includes a cleaning execution unit that executes a cleaning process and wherein the cleaning process includes a determination process of determining the presence or absence of a specific cartridge, among a plurality of cartridges, whose liquid remaining amount is equal to or greater than a reference remaining amount before performing the cleaning operation, and whose liquid remaining amount is expected to be less than the reference remaining amount when the cleaning operation is executed, and a setting process of setting the specific cartridge as a cartridge to be replaced before executing the cleaning operation.

A detection method for a liquid level of a storage tank is provided. The detection method determines that an optical sensor is for a liquid level detection purpose when a sensing value to a tank object is consistent with a first threshold condition. The detection method further determines the optical sensor as valid on liquid level detection when sensing values respectively corresponding to statuses of print material and non-print-material are consistent with a second threshold condition. During printing, the detection method starts/stops pouring print material into a storage tank when the sensing value of the optical sensor is consistent with a third threshold condition correspondingly.

In one example in accordance with the present disclosure, a print fluid delivery system is described. The print fluid delivery system includes a main reservoir to hold a volume of print fluid to be supplied to a printhead and a fluid indicator reservoir fluidly coupled to the main reservoir. The fluid indicator reservoir visually indicates a fluid level through an aperture in a printing system housing. The fluid indicator reservoir and the main reservoir have a same fluid level. The print fluid delivery system also includes a fluid transport system to transport fluid through the print fluid delivery system.

A printing fluid cartridge includes a front face oriented toward a first direction, a printing fluid supply portion positioned at the front face, a rear face positioned opposite the front face and oriented toward a second direction opposite the first direction, at least one electrical interface positioned between the front face and the rear face, and an engagement surface facing in the second direction. The at least one electrical interface is offset from the printing supply portion with respect to a third direction perpendicular to the first direction and the second direction. The at least one electrical interface is positioned closer to the front face than the engagement surface is, and the at least one electrical interface and the engagement surface intersect a plane which is parallel with the first direction, the second direction, and the third direction.

Example techniques for controlling a movement of a print carriage are described. In an example, in response to a determination that a movement of the print carriage in a printing device may be an unstable movement, a first movement parameter value may be associated with the movement of the print carriage, to prevent the unstable movement.

An example printing material cartridge may include an input/output device and a memory. The memory may store an identifier of the cartridge, a usage counter of the cartridge, and an indicator that the cartridge has reached a usage threshold. The memory may also store a usage offset equal to a historical usage of the cartridge, the usage offset for determining a new remaining usage of the cartridge.

A printing apparatus includes: a tank configured to contain ink; a print head configured to eject ink supplied from the tank; a supply flow path through which liquid is supplied from the tank to the print head; a collection flow path through which liquid is collected from the print head to the tank; a circulation unit configured to circulate ink inside a circulation flow path including the tank, the supply flow path, the print head, and the collection flow path; and a cooling unit configured to cool the tank by blowing.

A printing system includes an acquirer, a comparator, a calculator, and an allocator. The acquirer acquires the number of media printed by a first printing device installed at a first location. The comparator compares the number of printed media acquired by the acquirer with the number of media specified based on a billing amount. The calculator calculates a first number of printable media of the first printing device based on the comparison by the comparator. The allocator allocates at least a part of the first number of printable media calculated by the calculator as a second number of printable media to a second printing device installed at a second location. The second printing device can perform printing as a billing target based on the second number of printable media.

Provided are a substrate treating liquid supply unit for constantly maintaining a liquid level of a nozzle of an inkjet head unit through real-time water level measurement, and a substrate treating apparatus including the same. The substrate treating liquid supply unit includes: a first reservoir connected to an inkjet head unit for jetting a substrate treating liquid onto a substrate and providing the substrate treating liquid to the inkjet head unit; a water level sensor measuring a water level of the substrate treating liquid stored in the first reservoir; and a pressure control module compensating for a pressure provided to the first reservoir based on an amount variation in the water level of the substrate treating liquid, wherein a liquid level of a nozzle of the inkjet head unit is constantly maintained.