A thermal printer includes a thermal head, a temperature sensor, and a controller. The thermal head includes heat generation elements configured to generate heat to perform printing. The temperature sensor is disposed in the thermal printer. The controller is configured to alternately turns on and off the heat generation elements during an idle state of the thermal printer for a number of cycles with a predetermined on-time period in each cycle. The controller determines the number of cycles and the predetermined on-time period based on temperature data obtained by the temperature sensor, such that heat energy generated by the heat generation elements during each of the cycles in the idle state is lower than heat energy generated by the heat generation elements during printing of one line.

A thermal printer includes a thermal head, a temperature sensor, and a controller. The thermal head includes heat generation elements configured to generate heat to perform printing. The temperature sensor is disposed in the thermal printer. The controller is configured to alternately turns on and off the heat generation elements during an idle state of the thermal printer for a number of cycles with a predetermined on-time period in each cycle. The controller determines the number of cycles and the predetermined on-time period based on temperature data obtained by the temperature sensor, such that heat energy generated by the heat generation elements during each of the cycles in the idle state is lower than heat energy generated by the heat generation elements during printing of one 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.

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.

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.

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.

An imaging system includes first and second heaters configured to pre-heat a thermochromic coating. The first heater heats at least one of a substrate and the thermochromic coating disposed on the substrate. The second heater heats an ambient environment surrounding the thermochromic coating. The first and second heaters are configured to pre-heat the thermochromic coating to a temperature below a threshold temperature of the thermochromic coating. The system further includes a patterned heater configured to heat the pre-heated thermochromic coating to one or more temperatures above the threshold temperature according to a predetermined pattern.

An imaging system includes first and second heaters configured to pre-heat a thermochromic coating. The first heater heats at least one of a substrate and the thermochromic coating disposed on the substrate. The second heater heats an ambient environment surrounding the thermochromic coating. The first and second heaters are configured to pre-heat the thermochromic coating to a temperature below a threshold temperature of the thermochromic coating. The system further includes a patterned heater configured to heat the pre-heated thermochromic coating to one or more temperatures above the threshold temperature according to a predetermined pattern.

Examples disclosed herein relate to an imaging device. Examples include a method for increasing the temperature of the imaging device by determining an internal temperature of the imaging device; determining if a start-up routine is to be initiated; pausing the start-up routine if the internal temperature is below a threshold temperature; and energizing at least one of a fan or heating element of the imaging device when the internal temperature is below the threshold temperature.

At step S115, a printer control unit refers to a table using an average print duty as an input, and determines a saturation temperature and a drum preliminary heating temperature. In this example, since the saturation temperature and the preliminary heating temperature with respect to the print duty are stored as a table, the printer control unit refers to the table using the average print duty as the input, and determines the saturation temperature and the drum preliminary heating temperature. At step S120, the printer control unit investigates a current drum temperature based on a measurement result of a temperature sensor. Subsequently, at step S125, the drum is heated or cooled until it reaches, of the saturation temperature and the drum preliminary heating temperature, the temperature for which the difference with the current drum temperature is smaller.