| 摘要 |
PURPOSE:To restrain concurrent coloring of lower thermal coloring layer due to excess thermal energy at the time of recording of upper layer without lowering the printing speed. CONSTITUTION:When an yellow thermal coloring layer of thermal color recording material is recorded thermally, a bias pulse is split into two substantially equal subpulses. Gradation pulses are distributed to two groups corresponding to respective bias pulses without modifying the number or the width thereof and then they are fed to heating elements when a platen drum is rotating continuously. Magenta and cyan thermal coloring layers are also thermally recorded such that two peaks appear in the heating temperature when one pixel is recorded. This arrangement prevents dot separation phenomenon when low density region of deepest cyan thermal coloring layer is thermally recorded. |
