| 摘要 |
PURPOSE:To provide each image dot with a different energy and control printing density so as to produce a gradient recording by incorporating in a transfer surface a plurality of kinds of thermally expandable particles, each having a different expansion starting temperature. CONSTITUTION:When the heating resistor of a thermal head 360 is energized, Joule heat is generated and transmitted through a base film 450 of an ink ribbon 400 to a thermally meltable ink layer 410. The thermally meltable ink layer 410 is then melted by this heat into a liquid ink and, at the same time, the microcapsules 420 are expanded to be increased in volume. In doing so, the molten ink on the thermally meltable ink layer 410 is released from the surface of the ink ribbon 400 and forced against an uneven surface of recording paper P to be impressed thereon. A plurality of kinds of microcapsules 420, each having a different expansion temperature, is dispersed in the thermally meltable ink layer 410 and the energy applied to a thermal head 360 is controlled, whereby the microcapsules 420 are selectively expanded to change the amount of the ink impressed on the recording paper P. |
