| 摘要 |
PURPOSE:To enable recording speed to be enhanced and gradation characteristics to be optimized and stabilized, by a method wherein correction data obtained each time by calculations according to external conditions are stored into a memory, and are read from the memory at the time of recording. CONSTITUTION:Each time the external condition data such as the ambient temperature, the kinds of a transfer paper and a recording paper and melting characteristics of an ink are changed, the correction data indicating an energization time for heating resistors are outputted from a calculating part 21. The correction data comprise gradation number versus energization time characteristics varied for every one or several units of density to give an optimum recorded density characteristic according to the external condition data. Therefore, the width of a pulse outputted from a comparator 23 for comparing the level of the correction data with the level of a signal of one gradation data time period is gradually varied for every one or several units of density. An electric current is passed to the heating resistors R1-Rn for a period of time equivalent to the pulse duration, whereby gradation density control is performed. Accordingly, it is possible to contrive a higher recording speed and optimal and stable gradation characteristics. |
