| 摘要 |
PURPOSE:To enhance printing quality, by applying preheating pulses to each heat generating resistor of a thermal head, which comprises a plurality of heat generating resistors arrayed transversely, for one dot printing period based on printing data, and selectively applying heating pulses to the resistors after application of the preheating pulses. CONSTITUTION:In printing in the first dot line (a), all heat generating resistors 111-11n are preheated by applying preheating pulses thereto, and then those corresponding to dots to be printed are heated by applying heating pulses thereto. In the figure, the white circle 'O' denotes application of only the preheating pulses, whereas the shaded circle denotes application of the preheating pulses pulse application of the heating pulses. Next, in printing in the second dot line (b), only the resistors corresponding to data are preheated by the preheating pulses. Since the data for the second dot line is the same as that for the first dot line, heating by application of the heating pulses is inhibited. Then, in printing in the third dot line (c), only the resistors corresponding to data are preheated by the preheating pulses. For data corresponding to the dots which are not printed in the preceding printing, heating by application of the heating pulse is performed. |
