JPS6456571A - Handy printer - Google Patents

Abstract

PURPOSE:To correct the scatter of resistance values of thermal heads used as printing means, by providing a printing controlling means for setting a voltage application time for the thermal head to an optimum value on the basis of a velocity signal obtained by a velocity detecting means. CONSTITUTION:A trigger signal 11 is inputted from a printing controlling part of a handy printer. A printing signal 12 is outputted from a period of time determined by a time constant RXC, where R is the resistance based on a volume control resistor 8 and a trimmer resistor 9, and C is the capacitance of a capacitor 10. While a head driving IC 13 is in an ON state, an electric current is passed to a thermal head 14, and printing is conducted. Thus, a printing time can be determined by variably setting the volume control resistance and the trimmer resistance. Therefore, the printing time is reduced by controlling the trimmer resistance to a lower value, and can be increased by controlling the trimmer resistance to a higher value. By this, it is possible to maintain the value of energy actually applied to the thermal head at a uniform value.