A thermal printer includes heating elements that generate heat according to amounts of applied energy, an energy applier that applies energy to the heating elements, a memory that stores a gradation table where energy levels to be applied to the heating elements are set for gradation levels based on a relationship between dot area ratios of an image and the amounts of energy applied to the heating elements, and a controller that transfers control data multiple times to the energy applier based on the gradation table to control the amounts of energy to be applied by the energy applier to the heating elements, each of the control data corresponding to different amounts of energy.

A printer in one example includes a thermal printhead with resistive heating elements. A motor is provided in the printer for conveying paper to the thermal printhead. A power supply is provided to supply power to the thermal printhead and the motor. A processor is configured to cause the supply of power to the motor to be paused after the supply of power to the thermal printhead exceeds a power threshold value and then to resume the supply of power to the motor after a predetermined period of time elapses after the pause of the supply of power to the motor.

An example system for thermal energy determination can include a first controller comprising a processor and a non-transitory machine-readable medium (MRM) communicatively coupled to the processor. The non-transitory MRM can include instructions executable by the processor to cause the processor to receive relative humidity information of an environment of a thermal printing device, determine a colormap to a print media of the thermal printing device based on the relative humidity, and determine a particular thermal energy to apply to the print media based on the determined colormap.

Thermal printing on plastic cards where the energization of each individually energizable heating element of a thermal printhead is adjusted based on a temperature of the thermal printhead and a density of the pixel to be printed. For each pixel, the printhead temperature and the pixel density of a pixel to be printed are used to adjust the strobe pulse length that energizes the heating element to print that pixel. By compensating for both printhead temperature and pixel density, a tighter tolerance of the resulting printed densities is achieved.

Thermal printing on plastic cards where the energization of each individually energizable heating element of a thermal printhead is adjusted based on a temperature of the thermal printhead and a density of the pixel to be printed. For each pixel, the printhead temperature and the pixel density of a pixel to be printed are used to adjust the strobe pulse length that energizes the heating element to print that pixel. By compensating for both printhead temperature and pixel density, a tighter tolerance of the resulting printed densities is achieved.

A thermal printer according to one embodiment includes a thermal head, a temperature sensor, and a control unit. The thermal head includes a plurality of heating elements. The temperature sensor is provided in the thermal head and is configured to measure a temperature of the thermal head. The control unit is configured to control an amount of heat generated from the heating elements by determining a pulse supply time for which a pulse signal is supplied to the thermal head based on the temperature of the thermal head and a cumulative heat generation time of the thermal head.

A thermal printer according to one embodiment includes a thermal head, a temperature sensor, and a control unit. The thermal head includes a plurality of heating elements. The temperature sensor is provided in the thermal head and is configured to measure a temperature of the thermal head. The control unit is configured to control an amount of heat generated from the heating elements by determining a pulse supply time for which a pulse signal is supplied to the thermal head based on the temperature of the thermal head and a cumulative heat generation time of the thermal head.

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 thermal printer according to one embodiment includes a thermal head, a temperature sensor, and a control unit. The thermal head includes a plurality of heating elements. The temperature sensor is provided in the thermal head and is configured to measure a temperature of the thermal head. The control unit is configured to control an amount of heat generated from the heating elements by determining a pulse supply time for which a pulse signal is supplied to the thermal head based on the temperature of the thermal head and a cumulative heat generation time of the thermal head.