Thermal printheads need a power and/or a data cable to deliver energy to the thermal printhead to print. With a wireless thermal printhead, however, a printer can run without using a power or a data cable. By removing the cable, benefits include shrinking the printer size, increasing durability of the printer and making it easier to change a thermal printhead.

A printhead substrate, comprising an electrothermal transducer configured to heat a printing material, a first DMOS transistor configured to drive the electrothermal transducer, a MOS structure forming an anti-fuse element, a second DMOS transistor configured to write information in the anti-fuse element by causing an insulation breakdown of an insulating film of the MOS structure, and a driving unit consisted of at least one MOS transistor and configured to drive the second DMOS transistor.

Speed fluctuations are decreased with a simple method even when a stepping motor (100) having comparatively large torque fluctuations is used. A drive pulse modulating unit (112) which modulates the frequency of a drive pulse to be inputted to the stepping motor (100) is provided. The drive pulse modulating unit (112) modulates the constant frequency of the drive pulse such that the frequency of the drive pulse within excitation-phase one cycle of the stepping motor (100) is: low for a period that is, by cycle of the excitation-phase one cycle, before an excitation phase where the vibration of the stepping motor is the maximum; and high in an excitation phase that is by cycle subsequent to the excitation phase where the drive pulse frequency is low.

Speed fluctuations are decreased with a simple method even when a stepping motor (100) having comparatively large torque fluctuations is used. A drive pulse modulating unit (112) which modulates the frequency of a drive pulse to be inputted to the stepping motor (100) is provided. The drive pulse modulating unit (112) modulates the constant frequency of the drive pulse such that the frequency of the drive pulse within excitation-phase one cycle of the stepping motor (100) is: low for a period that is, by cycle of the excitation-phase one cycle, before an excitation phase where the vibration of the stepping motor is the maximum; and high in an excitation phase that is by cycle subsequent to the excitation phase where the drive pulse frequency is low.

An apparatus for determining the resistance of a printing element of a print head, the apparatus comprising: a print head comprising a plurality of individually controllable printing elements connected in parallel, and a capacitor connected in parallel with the printing elements; a test voltage supply arranged to supply a test voltage to the print head; a current monitor arranged to measure the current supplied to one of the printing elements when the said one of the printing elements is connected to the test voltage supply; and a controller arranged to determine the resistance of the said one of the printing elements based upon the measured current.

An apparatus for determining the resistance of a printing element of a print head, the apparatus comprising: a print head comprising a plurality of individually controllable printing elements connected in parallel, and a capacitor connected in parallel with the printing elements; a test voltage supply arranged to supply a test voltage to the print head; a current monitor arranged to measure the current supplied to one of the printing elements when the said one of the printing elements is connected to the test voltage supply; and a controller arranged to determine the resistance of the said one of the printing elements based upon the measured current.

A printhead substrate, comprising an electrothermal transducer configured to heat a printing material, a first DMOS transistor configured to drive the electrothermal transducer, a MOS structure forming an anti-fuse element, a second DMOS transistor configured to write information in the anti-fuse element by causing an insulation breakdown of an insulating film of the MOS structure, and a driving unit consisted of at least one MOS transistor and configured to drive the second DMOS transistor.

A printhead substrate, comprising an electrothermal transducer configured to heat a printing material, a first DMOS transistor configured to drive the electrothermal transducer, a MOS structure forming an anti-fuse element, a second DMOS transistor configured to write information in the anti-fuse element by causing an insulation breakdown of an insulating film of the MOS structure, and a driving unit consisted of at least one MOS transistor and configured to drive the second DMOS transistor.

A printer driven by power of a battery, the printer including a thermal head including a plurality of heating elements arranged along a direction perpendicular to a conveying direction, a drive unit to supply power to the thermal head to drive the thermal head, and a processor to control driving and perform printing on the recording medium according to printing data, in which the processor calculates, based on a state of its own printer, a printing cycle related to printing of each line for the line configuring the printing data and an energization time for supplying power to the thermal head within the printing cycle, adjusts the energization time according to a characteristic difference between an internal resistance of the reference battery and an internal resistance of the battery, and prints for one line by supplying power to the drive unit during the energization time after adjustment.

A printer driven by power of a battery, the printer including a thermal head including a plurality of heating elements arranged along a direction perpendicular to a conveying direction, a drive unit to supply power to the thermal head to drive the thermal head, and a processor to control driving and perform printing on the recording medium according to printing data, in which the processor calculates, based on a state of its own printer, a printing cycle related to printing of each line for the line configuring the printing data and an energization time for supplying power to the thermal head within the printing cycle, adjusts the energization time according to a characteristic difference between an internal resistance of the reference battery and an internal resistance of the battery, and prints for one line by supplying power to the drive unit during the energization time after adjustment.