US Patent 7466329 Printer device

A printer device that prints an image to a printing paper using a thermal head formed with a plurality of heating resistors. The printer device includes: edge position detection means for performing edge position detection to an incoming printing paper using the thermal head based on a change of temperature increase observed in, as a result of energization, any of the heating resistors opposing the printing paper and the remaining heating resistors not opposing the printing paper; and control means for exercising control over an image printing operation using the thermal head based on a detection output derived by the edge position detection means.