| 摘要 |
PURPOSE:To facilitate multi-gradation representation, by constructing with a plurality of pair electrodes having total width shorter than the effective recording width of heating elements and controlling the time for applying voltage onto the heating elements and the number of pair electrodes being employed for application of voltage. CONSTITUTION:A joint of an electrode 2 with a heating element 1 consists of a plurality of pair electrodes 2-1, 2-2, 2-3 having total width shorter than the effective recording width of said heating element. When the current level is lower than a predetermined level, almost all current flows to a lateral portion of the heating element 1 corresponding to the width of pair electrode 2-2 being applied with voltage; thereby, the temperature at said lateral portion increases particularly and the temperature difference between said lateral portion and other portions increases. When applying time of pulse voltage is increased gradually in order to vary the applying energy. ink is fused in an area hazing higher temperature th.n the melting point of an ink sheet and transferred to a recording sheet. Consequently. the area of dot being transferred can be varied by varying the pulse voltage application time and the number of driving electrodes, resulting in smooth modulation of dot area. |
