Serial thermal printing method

摘要

A thermal head has a plurality of heating elements disposed in line. These heating elements are grouped into sets of four heating elements. Each set records one pixel which is constituted by 4x8 cells disposed in a matrix shape. Each cell is selectively recorded with an ink micro dot. A blank section record an nth pixel, and immediately before each heating element faces the first main micro line of an (n+1)th pixel. In the course of this blank section, each time the thermal head moves by a predetermined distance, each heating element is driven by drive data which does not make the heating element turn on. In a preferred embodiment, if an nth pixel has a low density, each heating element is selectively driven to the extent that an ink micro dot is not recorded, so as to preheat the selected heating element in the course of the blank section.