Ink in a print head is heated to a target temperature by driving heating elements included in a print head. After heating control is completed, operation that is performed using power stored in a power storage unit is started. The target temperature in the heating control is determined in such a manner that the temperature of the print head when the operation is started is a set temperature or higher.

In some examples, printing device temperature management may include ascertaining a print speed associated with a print job, and comparing the print speed to a print speed threshold. Printing device temperature management may further include actuating a power supply associated with a print bar at a start position of physical medium to be utilized for printing for the print job, or at or beyond a specified location along a path associated with traversal of the physical medium from the start position to a print zone to reduce an operational temperature associated with the print bar.

In some examples, printing device temperature management may include ascertaining a print speed associated with a print job, and comparing the print speed to a print speed threshold. Printing device temperature management may further include actuating a power supply associated with a print bar at a start position of physical medium to be utilized for printing for the print job, or at or beyond a specified location along a path associated with traversal of the physical medium from the start position to a print zone to reduce an operational temperature associated with the print bar.

A droplet discharge apparatus may include a droplet discharge unit configured to discharge droplets of a target substance stored in a tank at intervals through an opening of a nozzle connected to the tank, a speed sensor configured to measure the speed of a droplet discharged from the droplet discharge unit, and a calculation unit configured to calculate the volume of the target substance consumed per unit time, based on cross-sectional area of the opening of the nozzle and the speed of the droplet.

A printing apparatus that performs printing by using a print head includes a first power supply, a second power supply, and a control unit. The first power supply supplies a first voltage to the print head through a first supply line. The second power supply supplies a second voltage to the print head through a second supply line. The control unit supplies the first voltage from the first power supply without supplying a voltage from the second power supply at the time of an inspection of the print head, and executes a process action concerning a current leakage when a voltage exceeding a predetermined first threshold is generated on the second supply line.

A fluid dispensing method, the method comprising steps of: providing a system comprising a reservoir, a micro-fluidic thermal inkjet print head in fluid communication with the reservoir, a controller and a power source in electrical communication with the controller and the print head, the reservoir containing a fluid, the micro-fluidic thermal inkjet print head comprising nozzles; heating the fluid in the microfluidic device to a temperature of about 40 C to 75 C in less than about 1000 ms; activating the print head to fire the nozzles about 200 fires/nozzle at a first frequency; subsequent to step c, activating the print head to fire the nozzles at a second frequency, the second frequency substantially less than the first frequency; and subsequent to step d, activating the print head to fire the nozzles at a third frequency substantially greater than the first frequency.

Heating is conducted sequentially by dividing a heating operation into first heating control and second heating control consuming higher electric power than that in the first heating control.

A recording apparatus that performs recording on a recording medium includes a low temperature marker that, depending on a change in temperature, changes a color state to a low-temperature first color state or to a low-temperature second color state different from the low-temperature first color state, and a surface on which the low temperature marker is disposed. The low temperature marker has a characteristic of indicating the low-temperature second color state when a temperature of the low temperature marker is higher than at least the low-temperature first threshold temperature after reached a temperature lower than or equal to a low-temperature first threshold temperature from an initial state indicating the low temperature first color state.

A method of atomizing a fluid composition is provided that includes dynamically measuring the minimum-required actuation energy for the fluid composition. The method includes the steps of: connecting a microfluidic cartridge with a housing of a microfluidic device, the microfluidic cartridge comprising a reservoir containing the fluid composition and a microfluidic die in fluid communication with the reservoir; the microfluidic device comprising a controller; measuring the minimum-required actuation energy for the fluid composition at a first time; atomizing the fluid composition in a first atomization period; measuring the minimum-required actuation energy for a fluid composition at a second time that is after the first time; and atomizing the fluid composition in a second atomization period.

Devices and method for performing temperature measurements in a printhead. In one embodiment, a printhead includes at least one row of jetting channels configured to jet droplets of a print fluid using piezoelectric actuators. A drive circuit includes an input voltage generator that applies a step voltage to a piezoelectric actuator of a jetting channel, and an output voltage detector that detects an output voltage across the piezoelectric actuator over time in response to the step voltage. The drive circuit also includes a temperature detector that determines a voltage response to the step voltage at the piezoelectric actuator based on the output voltage over time, and determines a temperature measurement for the piezoelectric actuator based on the voltage response of the piezoelectric actuator.