US Patent 7091999 Thermal printing apparatus and printing method

A printing apparatus including a thermal head, a measurement device that measures a temperature of the thermal head and a controller. The controller controls a printing speed on the basis of the measured temperature as measured by the measurement device, determines whether the measured temperature of the thermal head is rising or dropping, compares a preliminarily determined first threshold value with the measured temperature when the temperature is rising, compares a preliminarily determined second threshold value with the measured temperature when the temperature is dropping, controls printing by reducing the printing speed when the measured temperature is greater than the first threshold value, and controls printing by raising the printing speed when the measured temperature is less than the second threshold value.