A printing device includes a thermal head and a head controller. The head controller acquires a number of heater elements to energize based on the line print data, and determines an energization time of one or more heater elements corresponding to the line print data according to a result of comparison between the number of heater elements to energize and a first threshold, wherein in a case where a width of an ink ribbon heated by the energization is equal to or wider than a second threshold, the first threshold being set to be a value that is greater than a value that is set for the first threshold when the width of the ink ribbon heated by the energization is narrower than the second threshold.

A printing device includes a thermal head and a head controller. The head controller acquires a number of heater elements to energize based on the line print data, and determines an energization time of one or more heater elements corresponding to the line print data according to a result of comparison between the number of heater elements to energize and a first threshold, wherein in a case where a width of an ink ribbon heated by the energization is equal to or wider than a second threshold, the first threshold being set to be a value that is greater than a value that is set for the first threshold when the width of the ink ribbon heated by the energization is narrower than the second threshold.

A printing apparatus includes: a main body having a space therein, a thermal head arranged on a substrate provided in the space, the thermal head having heating elements arranged along a predetermined arrangement direction; a first conveyor which conveys an ink ribbon along a first conveyance path orthogonal to the arrangement direction, a second conveyor which conveys a printing object along a second conveyance path orthogonal to the arrangement direction and on an opposite side of the thermal head with respect to the first conveyance path, a first temperature sensor provided in a first space on a side of the thermal head with respect to the first conveyance path, a second temperature sensor provided in a second space between the first conveyance path and the second conveyance path, and a processor.

A printing apparatus includes: a main body having a space therein, a thermal head arranged on a substrate provided in the space, the thermal head having heating elements arranged along a predetermined arrangement direction; a first conveyor which conveys an ink ribbon along a first conveyance path orthogonal to the arrangement direction, a second conveyor which conveys a printing object along a second conveyance path orthogonal to the arrangement direction and on an opposite side of the thermal head with respect to the first conveyance path, a first temperature sensor provided in a first space on a side of the thermal head with respect to the first conveyance path, a second temperature sensor provided in a second space between the first conveyance path and the second conveyance path, and a processor.

A printing apparatus includes: a main-body having a space therein; a thermal head arranged on a substrate provided in the space, the thermal head having heating elements arranged along a predetermined arrangement direction; a conveyor which conveys a thermal paper along a conveyance path provided in the space and intersecting with the arrangement direction; a first temperature sensor provided in a first space in the space on a side of the thermal head with respect to the conveyance path; a second temperature sensor provided in a second space in the space on a side opposite to the thermal head with respect to the conveyance path; and a processor configured to: correct an amount of applying energy to be applied to the heating elements, based on first and second temperatures detected by the first and second temperature sensors; and apply corrected amount of the applying energy selectively to the heating elements.

A printing apparatus includes: a main body; a cassette including a cassette case and a printing medium accommodated in the cassette case; an installing portion provided on the main body for installing the cassette detachably; a thermal head arranged on a substrate provided in the installing portion and having heating elements arranged along a predetermined arrangement direction; a conveyor which conveys the printing medium of the cassette installed in the installing portion along a conveyance path orthogonal to the arrangement direction; a first temperature sensor provided, in the installing portion, on a side of the thermal head with respect to the conveyance path; a second temperature sensor provided in the interior of the cassette case or the installing portion; and a processor which corrects an amount of applying energy to be applied to the heating elements, based on first and second temperatures detected by the first and second temperature sensors.

A printing apparatus includes: a main body; a cassette including a cassette case and a printing medium accommodated in the cassette case; an installing portion provided on the main body for installing the cassette detachably; a thermal head arranged on a substrate provided in the installing portion and having heating elements arranged along a predetermined arrangement direction; a conveyor which conveys the printing medium of the cassette installed in the installing portion along a conveyance path orthogonal to the arrangement direction; a first temperature sensor provided, in the installing portion, on a side of the thermal head with respect to the conveyance path; a second temperature sensor provided in the interior of the cassette case or the installing portion; and a processor which corrects an amount of applying energy to be applied to the heating elements, based on first and second temperatures detected by the first and second temperature sensors.

A printing apparatus includes a thermal head and a processor. The thermal head has heat-generating elements and prints on a plurality of lines in a medium in setting periods. The processor sets a second period within each setting period. The second period is a time period for adjusting a temperature change of the heat-generating elements without printing, after a first period for printing. The processor determines a n.sup.th line (n: an integer of 1 or greater) among the lines based on printing data for printing the image. The n.sup.th line is a line estimated to have a possibility of sticking on the medium by the thermal head. The processor adjusts a temperature change of at least a part of the heat-generating elements in the second periods corresponding to at least the n.sup.th line and a (n+1).sup.th line, to suppress the sticking.

A printing apparatus includes a thermal head and a processor. The thermal head includes heat-generating elements and prints on a plurality of lines in a medium. The processor sets a second period within one of the setting periods. The second period is a time period for adjusting a temperature change of the heat-generating elements without printing on the medium, after a first period for printing. The processor determines a n.sup.th line (n: an integer of 2 or greater) among the lines based on printing data. The n.sup.th line is estimated to have a possibility of sticking in printing. The processor adjusts a temperature change of at least a part of the heat-generating elements in the second periods corresponding to at least the n.sup.th line and a (n1).sup.th line. The (n1).sup.th line is printed immediately before the n.sup.th line based on the printing data, to suppress the sticking.

A thermal printer according to an embodiment includes a communication interface that receives print data from an external device. A thermal print head thermally prints on a sheet, line by line according to the received print data. A motor drives a roller to transport the sheet, line by line according to the received print data. A processor determines, for a current print line, a target transport speed for transporting the sheet, and retrieves one or more intermediate speeds that are defined in advance and are between a current transport speed of transporting the sheet and the target transport speed. The processor controls the motor to transport the sheet at each determined intermediate speed and the target transport speed, sequentially. The thermal print head is heated in accordance with predetermined heating control information corresponding to the determined intermediate speed closest to the current speed.