| 摘要 |
PURPOSE:To obtain a thermal head having steep temp. characteristics, forming a color image with good quality and having no possibility such that early stage abrasion and the feed-irregularity of heat-sensitive paper are generated, by providing grooves to both sides of a glass layer at a part where the glass layer is opposed to a heat generator. CONSTITUTION:A pair of grooves 7 are provided to both sides of the glass layer 2'' on an alumina substrate 1 at a part corresponding to a minute section (l) where a heat generator part 6'' must be constituted. Thus constituted thermal head is low in heat capacity at the part provided between the grooves 7, 7 because the glass layer 2'' in the vicinity of the heat generator part 6'' is separated from the peripheral part thereof through the grooves 7 and the heat conduction to said glass layer 2'' is suppressed and the temp. characteristics thereof become steep as shown by the curve C2. Therefore, a color image with good quality is obtained on heat-sensitive paper. In addition, the heat- sensitive part 9 is held between the thermal head and the protective layer 5'' of a platen roller 8 over the range W where the platen rooler 8 wider than the width (s) between the grooves 7 is crushed. As a result, there is no possibility of generating feed irregularity of the heat-sensitive paper 9 and early stage abrasion caused by local pressure.
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