| 摘要 |
PURPOSE:To obtain a recording image having high resolving power not affected by a printing speed, by controlling printing history at every dot on the basis of the printing history period from the printing of the previous time to the next printing and controlling a printing pulse width corresponding to said printing history period. CONSTITUTION:When a printing pulse having a certain width is applied to the heat generating resistor 102 of a thermal recording head, the temp. of the heat generating resistor 102 rises and, when the printing pulse is cut off the temp. of the heat generating resistor 102 falls according to an approximately determinable exponential function characteristic. Therefore, when said exponential function can be calculated, the printing history (heat accumulation temp.) of each beat generating resistor 102 can be controlled on the basis of the time (printing history period) from the time immediately after printing at every heat generating resistor 102 (dot) to the next printing. By this method, the width of the printing pulse to be applied to said heat generating resistor 102 is selectively determined so as to uniformize the heat accumulation temp. of each heat generating resistor 102. |
