| 摘要 |
PURPOSE:To suppress heat accumulation during continuous energization and obtain favorable printing quality, by measuring a reference energization time by a measuring means at least once per line or page, and determining the energy to be applied to each that generating element on the basis of the result of measurement. CONSTITUTION:Each pulse width is calculated by multiplying the pulse width TW of an output from a reference energization width controlling circuit 40 by a coefficient K. Values of the coefficient K are stored in an applied energy discrimination table 38 in a ROM 37. The value of the coefficient K is not limited to those stored in the table, and an optimum value is determined from actual printing quality. The energization period of time where the preceding two dots have been ON is set to be T3, the energization period of time where the last dot has been ON is set to be T2+T3, the energization time where the dot before the last dot has been ON and the last dot has been OFF is set to be T1+T3, and the energization times are so set as to satisfy T3<T2+T3< T1+T3. With this setting, it is possible to perform a control conforming to the current temperature condition of each heat generating element, and to sufficiently enhance printing quality in each minute section in printing one line. |
